View Source NaiveDateTime (Elixir v1.15.0-dev)

A NaiveDateTime struct (without a time zone) and functions.

The NaiveDateTime struct contains the fields year, month, day, hour, minute, second, microsecond and calendar. New naive datetimes can be built with the new/2 and new/8 functions or using the ~N (see sigil_N/2) sigil:

iex> ~N[2000-01-01 23:00:07]
~N[2000-01-01 23:00:07]

The date and time fields in the struct can be accessed directly:

iex> naive = ~N[2000-01-01 23:00:07]
iex> naive.year
2000
iex> naive.second
7

We call them "naive" because this datetime representation does not have a time zone. This means the datetime may not actually exist in certain areas in the world even though it is valid.

For example, when daylight saving changes are applied by a region, the clock typically moves forward or backward by one hour. This means certain datetimes never occur or may occur more than once. Since NaiveDateTime is not validated against a time zone, such errors would go unnoticed.

Developers should avoid creating the NaiveDateTime structs directly and instead, rely on the functions provided by this module as well as the ones in third-party calendar libraries.

comparing-naive-date-times

Comparing naive date times

Comparisons in Elixir using ==/2, >/2, </2 and similar are structural and based on the NaiveDateTime struct fields. For proper comparison between naive datetimes, use the compare/2 function. The existence of the compare/2 function in this module also allows using Enum.min/2 and Enum.max/2 functions to get the minimum and maximum naive datetime of an Enum. For example:

iex> Enum.min([~N[2020-01-01 23:00:07], ~N[2000-01-01 23:00:07]], NaiveDateTime)
~N[2000-01-01 23:00:07]

using-epochs

Using epochs

The add/3 and diff/3 functions can be used for computing date times or retrieving the number of seconds between instants. For example, if there is an interest in computing the number of seconds from the Unix epoch (1970-01-01 00:00:00):

iex> NaiveDateTime.diff(~N[2010-04-17 14:00:00], ~N[1970-01-01 00:00:00])
1271512800

iex> NaiveDateTime.add(~N[1970-01-01 00:00:00], 1_271_512_800)
~N[2010-04-17 14:00:00]

Those functions are optimized to deal with common epochs, such as the Unix Epoch above or the Gregorian Epoch (0000-01-01 00:00:00).

Link to this section Summary

Functions

Returns true if the first NaiveDateTime is strictly later than the second.

Returns true if the first NaiveDateTime is strictly earlier than the second.

Converts the given naive_datetime from one calendar to another.

Converts the given naive_datetime from one calendar to another.

Subtracts naive_datetime2 from naive_datetime1.

Parses the extended "Date and time of day" format described by ISO 8601:2019.

Parses the extended "Date and time of day" format described by ISO 8601:2019.

Returns the "local time" for the machine the Elixir program is running on.

Builds a naive datetime from date and time structs.

Builds a naive datetime from date and time structs.

Converts a NaiveDateTime into a Date.

Converts a NaiveDateTime struct to an Erlang datetime tuple.

Converts a NaiveDateTime struct to a number of gregorian seconds and microseconds.

Converts the given naive datetime to ISO 8601:2019.

Converts the given naive datetime to a string according to its calendar.

Converts a NaiveDateTime into Time.

Returns the given naive datetime with the microsecond field truncated to the given precision (:microsecond, :millisecond or :second).

Returns the current naive datetime in UTC.

Link to this section Types

@type t() :: %NaiveDateTime{
  calendar: Calendar.calendar(),
  day: Calendar.day(),
  hour: Calendar.hour(),
  microsecond: Calendar.microsecond(),
  minute: Calendar.minute(),
  month: Calendar.month(),
  second: Calendar.second(),
  year: Calendar.year()
}

Link to this section Functions

Link to this function

add(naive_datetime, amount_to_add, unit \\ :second)

View Source (since 1.4.0)
@spec add(
  Calendar.naive_datetime(),
  integer(),
  :day | :hour | :minute | System.time_unit()
) :: t()

Adds a specified amount of time to a NaiveDateTime.

Accepts an amount_to_add in any unit. unit can be :day, :hour, :minute, :second or any subsecond precision from System.time_unit/0. It defaults to :second. Negative values will move backwards in time.

This function always consider the unit to be computed according to the Calendar.ISO.

examples

Examples

It uses seconds by default:

# adds seconds by default
iex> NaiveDateTime.add(~N[2014-10-02 00:29:10], 2)
~N[2014-10-02 00:29:12]

# accepts negative offsets
iex> NaiveDateTime.add(~N[2014-10-02 00:29:10], -2)
~N[2014-10-02 00:29:08]

It can also work with subsecond precisions:

iex> NaiveDateTime.add(~N[2014-10-02 00:29:10], 2_000, :millisecond)
~N[2014-10-02 00:29:12]

As well as days/hours/minutes:

iex> NaiveDateTime.add(~N[2015-02-28 00:29:10], 2, :day)
~N[2015-03-02 00:29:10]
iex> NaiveDateTime.add(~N[2015-02-28 00:29:10], 36, :hour)
~N[2015-03-01 12:29:10]
iex> NaiveDateTime.add(~N[2015-02-28 00:29:10], 60, :minute)
~N[2015-02-28 01:29:10]

This operation keeps the precision of the naive date time:

iex> NaiveDateTime.add(~N[2014-10-02 00:29:10.021], 21, :second)
~N[2014-10-02 00:29:31.021]

And ignores any changes below the precision:

iex> hidden = NaiveDateTime.add(~N[2014-10-02 00:29:10], 21, :millisecond)
iex> hidden.microsecond # ~N[2014-10-02 00:29:10]
{21000, 0}

Operations on top of gregorian seconds or the Unix epoch are optimized:

# from Gregorian seconds
iex> NaiveDateTime.add(~N[0000-01-01 00:00:00], 63_579_428_950)
~N[2014-10-02 00:29:10]

Passing a DateTime automatically converts it to NaiveDateTime, discarding the time zone information:

iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
...>                utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
iex> NaiveDateTime.add(dt, 21, :second)
~N[2000-02-29 23:00:28]
Link to this function

after?(naive_datetime1, naive_datetime2)

View Source (since 1.15.0)

Returns true if the first NaiveDateTime is strictly later than the second.

examples

Examples

iex> NaiveDateTime.after?(~N[2022-02-02 11:00:00], ~N[2021-01-01 11:00:00])
true
iex> NaiveDateTime.after?(~N[2021-01-01 11:00:00], ~N[2021-01-01 11:00:00])
false
iex> NaiveDateTime.after?(~N[2021-01-01 11:00:00], ~N[2022-02-02 11:00:00])
false
Link to this function

before?(naive_datetime1, naive_datetime2)

View Source (since 1.15.0)

Returns true if the first NaiveDateTime is strictly earlier than the second.

examples

Examples

iex> NaiveDateTime.before?(~N[2021-01-01 11:00:00], ~N[2022-02-02 11:00:00])
true
iex> NaiveDateTime.before?(~N[2021-01-01 11:00:00], ~N[2021-01-01 11:00:00])
false
iex> NaiveDateTime.before?(~N[2022-02-02 11:00:00], ~N[2021-01-01 11:00:00])
false
Link to this function

compare(naive_datetime1, naive_datetime2)

View Source (since 1.4.0)
@spec compare(Calendar.naive_datetime(), Calendar.naive_datetime()) :: :lt | :eq | :gt

Compares two NaiveDateTime structs.

Returns :gt if first is later than the second and :lt for vice versa. If the two NaiveDateTime are equal :eq is returned.

examples

Examples

iex> NaiveDateTime.compare(~N[2016-04-16 13:30:15], ~N[2016-04-28 16:19:25])
:lt
iex> NaiveDateTime.compare(~N[2016-04-16 13:30:15.1], ~N[2016-04-16 13:30:15.01])
:gt

This function can also be used to compare a DateTime without the time zone information:

iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
...>                utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
iex> NaiveDateTime.compare(dt, ~N[2000-02-29 23:00:07])
:eq
iex> NaiveDateTime.compare(dt, ~N[2000-01-29 23:00:07])
:gt
iex> NaiveDateTime.compare(dt, ~N[2000-03-29 23:00:07])
:lt
Link to this function

convert(naive_datetime, calendar)

View Source (since 1.5.0)
@spec convert(Calendar.naive_datetime(), Calendar.calendar()) ::
  {:ok, t()} | {:error, :incompatible_calendars}

Converts the given naive_datetime from one calendar to another.

If it is not possible to convert unambiguously between the calendars (see Calendar.compatible_calendars?/2), an {:error, :incompatible_calendars} tuple is returned.

examples

Examples

Imagine someone implements Calendar.Holocene, a calendar based on the Gregorian calendar that adds exactly 10,000 years to the current Gregorian year:

iex> NaiveDateTime.convert(~N[2000-01-01 13:30:15], Calendar.Holocene)
{:ok, %NaiveDateTime{calendar: Calendar.Holocene, year: 12000, month: 1, day: 1,
                     hour: 13, minute: 30, second: 15, microsecond: {0, 0}}}
Link to this function

convert!(naive_datetime, calendar)

View Source (since 1.5.0)
@spec convert!(Calendar.naive_datetime(), Calendar.calendar()) :: t()

Converts the given naive_datetime from one calendar to another.

If it is not possible to convert unambiguously between the calendars (see Calendar.compatible_calendars?/2), an ArgumentError is raised.

examples

Examples

Imagine someone implements Calendar.Holocene, a calendar based on the Gregorian calendar that adds exactly 10,000 years to the current Gregorian year:

iex> NaiveDateTime.convert!(~N[2000-01-01 13:30:15], Calendar.Holocene)
%NaiveDateTime{calendar: Calendar.Holocene, year: 12000, month: 1, day: 1,
               hour: 13, minute: 30, second: 15, microsecond: {0, 0}}
Link to this function

diff(naive_datetime1, naive_datetime2, unit \\ :second)

View Source (since 1.4.0)
@spec diff(
  Calendar.naive_datetime(),
  Calendar.naive_datetime(),
  :day | :hour | :minute | System.time_unit()
) :: integer()

Subtracts naive_datetime2 from naive_datetime1.

The answer can be returned in any :day, :hour, :minute, or any unit available from System.time_unit/0. The unit is measured according to Calendar.ISO and defaults to :second.

Fractional results are not supported and are truncated.

examples

Examples

iex> NaiveDateTime.diff(~N[2014-10-02 00:29:12], ~N[2014-10-02 00:29:10])
2
iex> NaiveDateTime.diff(~N[2014-10-02 00:29:12], ~N[2014-10-02 00:29:10], :microsecond)
2_000_000

iex> NaiveDateTime.diff(~N[2014-10-02 00:29:10.042], ~N[2014-10-02 00:29:10.021])
0
iex> NaiveDateTime.diff(~N[2014-10-02 00:29:10.042], ~N[2014-10-02 00:29:10.021], :millisecond)
21

iex> NaiveDateTime.diff(~N[2014-10-02 00:29:10], ~N[2014-10-02 00:29:12])
-2
iex> NaiveDateTime.diff(~N[-0001-10-02 00:29:10], ~N[-0001-10-02 00:29:12])
-2

It can also compute the difference in days, hours, or minutes:

iex> NaiveDateTime.diff(~N[2014-10-10 00:29:10], ~N[2014-10-02 00:29:10], :day)
8
iex> NaiveDateTime.diff(~N[2014-10-02 12:29:10], ~N[2014-10-02 00:29:10], :hour)
12
iex> NaiveDateTime.diff(~N[2014-10-02 00:39:10], ~N[2014-10-02 00:29:10], :minute)
10

But it also rounds incomplete days to zero:

iex> NaiveDateTime.diff(~N[2014-10-10 00:29:09], ~N[2014-10-02 00:29:10], :day)
7
Link to this function

from_erl(tuple, microsecond \\ {0, 0}, calendar \\ Calendar.ISO)

View Source
@spec from_erl(:calendar.datetime(), Calendar.microsecond(), Calendar.calendar()) ::
  {:ok, t()} | {:error, atom()}

Converts an Erlang datetime tuple to a NaiveDateTime struct.

Attempting to convert an invalid ISO calendar date will produce an error tuple.

examples

Examples

iex> NaiveDateTime.from_erl({{2000, 1, 1}, {13, 30, 15}})
{:ok, ~N[2000-01-01 13:30:15]}
iex> NaiveDateTime.from_erl({{2000, 1, 1}, {13, 30, 15}}, {5000, 3})
{:ok, ~N[2000-01-01 13:30:15.005]}
iex> NaiveDateTime.from_erl({{2000, 13, 1}, {13, 30, 15}})
{:error, :invalid_date}
iex> NaiveDateTime.from_erl({{2000, 13, 1}, {13, 30, 15}})
{:error, :invalid_date}
Link to this function

from_erl!(tuple, microsecond \\ {0, 0}, calendar \\ Calendar.ISO)

View Source

Converts an Erlang datetime tuple to a NaiveDateTime struct.

Raises if the datetime is invalid. Attempting to convert an invalid ISO calendar date will produce an error tuple.

examples

Examples

iex> NaiveDateTime.from_erl!({{2000, 1, 1}, {13, 30, 15}})
~N[2000-01-01 13:30:15]
iex> NaiveDateTime.from_erl!({{2000, 1, 1}, {13, 30, 15}}, {5000, 3})
~N[2000-01-01 13:30:15.005]
iex> NaiveDateTime.from_erl!({{2000, 13, 1}, {13, 30, 15}})
** (ArgumentError) cannot convert {{2000, 13, 1}, {13, 30, 15}} to naive datetime, reason: :invalid_date
Link to this function

from_gregorian_seconds(seconds, arg \\ {0, 0}, calendar \\ Calendar.ISO)

View Source (since 1.11.0)
@spec from_gregorian_seconds(integer(), Calendar.microsecond(), Calendar.calendar()) ::
  t()

Converts a number of gregorian seconds to a NaiveDateTime struct.

examples

Examples

iex> NaiveDateTime.from_gregorian_seconds(1)
~N[0000-01-01 00:00:01]
iex> NaiveDateTime.from_gregorian_seconds(63_755_511_991, {5000, 3})
~N[2020-05-01 00:26:31.005]
iex> NaiveDateTime.from_gregorian_seconds(-1)
~N[-0001-12-31 23:59:59]
Link to this function

from_iso8601(string, calendar \\ Calendar.ISO)

View Source
@spec from_iso8601(String.t(), Calendar.calendar()) :: {:ok, t()} | {:error, atom()}

Parses the extended "Date and time of day" format described by ISO 8601:2019.

Time zone offset may be included in the string but they will be simply discarded as such information is not included in naive date times.

As specified in the standard, the separator "T" may be omitted if desired as there is no ambiguity within this function.

Note leap seconds are not supported by the built-in Calendar.ISO.

examples

Examples

iex> NaiveDateTime.from_iso8601("2015-01-23 23:50:07")
{:ok, ~N[2015-01-23 23:50:07]}
iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07")
{:ok, ~N[2015-01-23 23:50:07]}
iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07Z")
{:ok, ~N[2015-01-23 23:50:07]}

iex> NaiveDateTime.from_iso8601("2015-01-23 23:50:07.0")
{:ok, ~N[2015-01-23 23:50:07.0]}
iex> NaiveDateTime.from_iso8601("2015-01-23 23:50:07,0123456")
{:ok, ~N[2015-01-23 23:50:07.012345]}
iex> NaiveDateTime.from_iso8601("2015-01-23 23:50:07.0123456")
{:ok, ~N[2015-01-23 23:50:07.012345]}
iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07.123Z")
{:ok, ~N[2015-01-23 23:50:07.123]}

iex> NaiveDateTime.from_iso8601("2015-01-23P23:50:07")
{:error, :invalid_format}
iex> NaiveDateTime.from_iso8601("2015:01:23 23-50-07")
{:error, :invalid_format}
iex> NaiveDateTime.from_iso8601("2015-01-23 23:50:07A")
{:error, :invalid_format}
iex> NaiveDateTime.from_iso8601("2015-01-23 23:50:61")
{:error, :invalid_time}
iex> NaiveDateTime.from_iso8601("2015-01-32 23:50:07")
{:error, :invalid_date}

iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07.123+02:30")
{:ok, ~N[2015-01-23 23:50:07.123]}
iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07.123+00:00")
{:ok, ~N[2015-01-23 23:50:07.123]}
iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07.123-02:30")
{:ok, ~N[2015-01-23 23:50:07.123]}
iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07.123-00:00")
{:error, :invalid_format}
iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07.123-00:60")
{:error, :invalid_format}
iex> NaiveDateTime.from_iso8601("2015-01-23T23:50:07.123-24:00")
{:error, :invalid_format}
Link to this function

from_iso8601!(string, calendar \\ Calendar.ISO)

View Source
@spec from_iso8601!(String.t(), Calendar.calendar()) :: t()

Parses the extended "Date and time of day" format described by ISO 8601:2019.

Raises if the format is invalid.

examples

Examples

iex> NaiveDateTime.from_iso8601!("2015-01-23T23:50:07.123Z")
~N[2015-01-23 23:50:07.123]
iex> NaiveDateTime.from_iso8601!("2015-01-23T23:50:07,123Z")
~N[2015-01-23 23:50:07.123]
iex> NaiveDateTime.from_iso8601!("2015-01-23P23:50:07")
** (ArgumentError) cannot parse "2015-01-23P23:50:07" as naive datetime, reason: :invalid_format
Link to this function

local_now(calendar \\ Calendar.ISO)

View Source (since 1.10.0)
@spec local_now(Calendar.calendar()) :: t()

Returns the "local time" for the machine the Elixir program is running on.

WARNING: This function can cause insidious bugs. It depends on the time zone configuration at run time. This can changed and be set to a time zone that has daylight saving jumps (spring forward or fall back).

This function can be used to display what the time is right now for the time zone configuration that the machine happens to have. An example would be a desktop program displaying a clock to the user. For any other uses it is probably a bad idea to use this function.

For most cases, use DateTime.now/2 or DateTime.utc_now/1 instead.

Does not include fractional seconds.

examples

Examples

iex> naive_datetime = NaiveDateTime.local_now()
iex> naive_datetime.year >= 2019
true
@spec new(Date.t(), Time.t()) :: {:ok, t()}

Builds a naive datetime from date and time structs.

examples

Examples

iex> NaiveDateTime.new(~D[2010-01-13], ~T[23:00:07.005])
{:ok, ~N[2010-01-13 23:00:07.005]}
Link to this function

new(year, month, day, hour, minute, second, microsecond \\ {0, 0}, calendar \\ Calendar.ISO)

View Source

Builds a new ISO naive datetime.

Expects all values to be integers. Returns {:ok, naive_datetime} if each entry fits its appropriate range, returns {:error, reason} otherwise.

examples

Examples

iex> NaiveDateTime.new(2000, 1, 1, 0, 0, 0)
{:ok, ~N[2000-01-01 00:00:00]}
iex> NaiveDateTime.new(2000, 13, 1, 0, 0, 0)
{:error, :invalid_date}
iex> NaiveDateTime.new(2000, 2, 29, 0, 0, 0)
{:ok, ~N[2000-02-29 00:00:00]}
iex> NaiveDateTime.new(2000, 2, 30, 0, 0, 0)
{:error, :invalid_date}
iex> NaiveDateTime.new(2001, 2, 29, 0, 0, 0)
{:error, :invalid_date}

iex> NaiveDateTime.new(2000, 1, 1, 23, 59, 59, {0, 1})
{:ok, ~N[2000-01-01 23:59:59.0]}
iex> NaiveDateTime.new(2000, 1, 1, 23, 59, 59, 999_999)
{:ok, ~N[2000-01-01 23:59:59.999999]}
iex> NaiveDateTime.new(2000, 1, 1, 24, 59, 59, 999_999)
{:error, :invalid_time}
iex> NaiveDateTime.new(2000, 1, 1, 23, 60, 59, 999_999)
{:error, :invalid_time}
iex> NaiveDateTime.new(2000, 1, 1, 23, 59, 60, 999_999)
{:error, :invalid_time}
iex> NaiveDateTime.new(2000, 1, 1, 23, 59, 59, 1_000_000)
{:error, :invalid_time}

iex> NaiveDateTime.new(2000, 1, 1, 23, 59, 59, {0, 1}, Calendar.ISO)
{:ok, ~N[2000-01-01 23:59:59.0]}
Link to this function

new!(date, time)

View Source (since 1.11.0)
@spec new!(Date.t(), Time.t()) :: t()

Builds a naive datetime from date and time structs.

examples

Examples

iex> NaiveDateTime.new!(~D[2010-01-13], ~T[23:00:07.005])
~N[2010-01-13 23:00:07.005]
Link to this function

new!(year, month, day, hour, minute, second, microsecond \\ {0, 0}, calendar \\ Calendar.ISO)

View Source (since 1.11.0)

Builds a new ISO naive datetime.

Expects all values to be integers. Returns naive_datetime if each entry fits its appropriate range, raises if time or date is invalid.

examples

Examples

iex> NaiveDateTime.new!(2000, 1, 1, 0, 0, 0)
~N[2000-01-01 00:00:00]
iex> NaiveDateTime.new!(2000, 2, 29, 0, 0, 0)
~N[2000-02-29 00:00:00]
iex> NaiveDateTime.new!(2000, 1, 1, 23, 59, 59, {0, 1})
~N[2000-01-01 23:59:59.0]
iex> NaiveDateTime.new!(2000, 1, 1, 23, 59, 59, 999_999)
~N[2000-01-01 23:59:59.999999]
iex> NaiveDateTime.new!(2000, 1, 1, 23, 59, 59, {0, 1}, Calendar.ISO)
~N[2000-01-01 23:59:59.0]
iex> NaiveDateTime.new!(2000, 1, 1, 24, 59, 59, 999_999)
** (ArgumentError) cannot build naive datetime, reason: :invalid_time
@spec to_date(Calendar.naive_datetime()) :: Date.t()

Converts a NaiveDateTime into a Date.

Because Date does not hold time information, data will be lost during the conversion.

examples

Examples

iex> NaiveDateTime.to_date(~N[2002-01-13 23:00:07])
~D[2002-01-13]

Converts a NaiveDateTime struct to an Erlang datetime tuple.

Only supports converting naive datetimes which are in the ISO calendar, attempting to convert naive datetimes from other calendars will raise.

WARNING: Loss of precision may occur, as Erlang time tuples only store hour/minute/second.

examples

Examples

iex> NaiveDateTime.to_erl(~N[2000-01-01 13:30:15])
{{2000, 1, 1}, {13, 30, 15}}

This function can also be used to convert a DateTime to an Erlang datetime tuple without the time zone information:

iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
...>                utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
iex> NaiveDateTime.to_erl(dt)
{{2000, 2, 29}, {23, 00, 07}}
Link to this function

to_gregorian_seconds(map)

View Source (since 1.11.0)
@spec to_gregorian_seconds(Calendar.naive_datetime()) ::
  {integer(), non_neg_integer()}

Converts a NaiveDateTime struct to a number of gregorian seconds and microseconds.

examples

Examples

iex> NaiveDateTime.to_gregorian_seconds(~N[0000-01-01 00:00:01])
{1, 0}
iex> NaiveDateTime.to_gregorian_seconds(~N[2020-05-01 00:26:31.005])
{63_755_511_991, 5000}
Link to this function

to_iso8601(naive_datetime, format \\ :extended)

View Source
@spec to_iso8601(Calendar.naive_datetime(), :basic | :extended) :: String.t()

Converts the given naive datetime to ISO 8601:2019.

By default, NaiveDateTime.to_iso8601/2 returns naive datetimes formatted in the "extended" format, for human readability. It also supports the "basic" format through passing the :basic option.

Only supports converting naive datetimes which are in the ISO calendar, attempting to convert naive datetimes from other calendars will raise.

examples

Examples

iex> NaiveDateTime.to_iso8601(~N[2000-02-28 23:00:13])
"2000-02-28T23:00:13"

iex> NaiveDateTime.to_iso8601(~N[2000-02-28 23:00:13.001])
"2000-02-28T23:00:13.001"

iex> NaiveDateTime.to_iso8601(~N[2000-02-28 23:00:13.001], :basic)
"20000228T230013.001"

This function can also be used to convert a DateTime to ISO 8601 without the time zone information:

iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
...>                utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
iex> NaiveDateTime.to_iso8601(dt)
"2000-02-29T23:00:07"
Link to this function

to_string(naive_datetime)

View Source
@spec to_string(Calendar.naive_datetime()) :: String.t()

Converts the given naive datetime to a string according to its calendar.

examples

Examples

iex> NaiveDateTime.to_string(~N[2000-02-28 23:00:13])
"2000-02-28 23:00:13"
iex> NaiveDateTime.to_string(~N[2000-02-28 23:00:13.001])
"2000-02-28 23:00:13.001"
iex> NaiveDateTime.to_string(~N[-0100-12-15 03:20:31])
"-0100-12-15 03:20:31"

This function can also be used to convert a DateTime to a string without the time zone information:

iex> dt = %DateTime{year: 2000, month: 2, day: 29, zone_abbr: "CET",
...>                hour: 23, minute: 0, second: 7, microsecond: {0, 0},
...>                utc_offset: 3600, std_offset: 0, time_zone: "Europe/Warsaw"}
iex> NaiveDateTime.to_string(dt)
"2000-02-29 23:00:07"
@spec to_time(Calendar.naive_datetime()) :: Time.t()

Converts a NaiveDateTime into Time.

Because Time does not hold date information, data will be lost during the conversion.

examples

Examples

iex> NaiveDateTime.to_time(~N[2002-01-13 23:00:07])
~T[23:00:07]
Link to this function

truncate(naive_datetime, precision)

View Source (since 1.6.0)
@spec truncate(t(), :microsecond | :millisecond | :second) :: t()

Returns the given naive datetime with the microsecond field truncated to the given precision (:microsecond, :millisecond or :second).

The given naive datetime is returned unchanged if it already has lower precision than the given precision.

examples

Examples

iex> NaiveDateTime.truncate(~N[2017-11-06 00:23:51.123456], :microsecond)
~N[2017-11-06 00:23:51.123456]

iex> NaiveDateTime.truncate(~N[2017-11-06 00:23:51.123456], :millisecond)
~N[2017-11-06 00:23:51.123]

iex> NaiveDateTime.truncate(~N[2017-11-06 00:23:51.123456], :second)
~N[2017-11-06 00:23:51]
Link to this function

utc_now(calendar \\ Calendar.ISO)

View Source (since 1.4.0)
@spec utc_now(Calendar.calendar()) :: t()

Returns the current naive datetime in UTC.

Prefer using DateTime.utc_now/0 when possible as, opposite to NaiveDateTime, it will keep the time zone information.

examples

Examples

iex> naive_datetime = NaiveDateTime.utc_now()
iex> naive_datetime.year >= 2016
true