Elixir v1.6.0-dev Time View Source

A Time struct and functions.

The Time struct contains the fields hour, minute, second and microseconds. New times can be built with the new/4 function or using the ~T sigil:

iex> ~T[23:00:07.001]
~T[23:00:07.001]

Both new/4 and sigil return a struct where the time fields can be accessed directly:

iex> time = ~T[23:00:07.001]
iex> time.hour
23
iex> time.microsecond
{1000, 3}

The functions on this module work with the Time struct as well as any struct that contains the same fields as the Time struct, such as NaiveDateTime and DateTime. Such functions expect Calendar.time/0 in their typespecs (instead of t/0).

Developers should avoid creating the Time structs directly and instead rely on the functions provided by this module as well as the ones in 3rd party calendar libraries.

Comparing times

Comparisons in Elixir using ==, >, < and similar are structural and based on the Time struct fields. For proper comparison between times, use the compare/2 function.

Link to this section Summary

Functions

Compares two time structs

Converts given time to a different calendar

Similar to Time.convert/2, but raises an ArgumentError if the conversion between the two calendars is not possible

Returns the difference between two times, considering only the hour, minute second and microsecond

Parses the extended “Local time” format described by ISO 8601:2004

Parses the extended “Local time” format described by ISO 8601:2004

Converts given time to an Erlang time tuple

Converts the given time to a string

Returns the current time in UTC

Link to this section Types

Link to this section Functions

Link to this function compare(time1, time2) View Source
compare(Calendar.time, Calendar.time) :: :lt | :eq | :gt

Compares two time structs.

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

Examples

iex> Time.compare(~T[16:04:16], ~T[16:04:28])
:lt
iex> Time.compare(~T[16:04:16], ~T[16:04:16])
:eq
iex> Time.compare(~T[16:04:16.01], ~T[16:04:16.001])
:gt

This function can also be used to compare across more complex calendar types by considering only the time fields:

iex> Time.compare(~N[1900-01-01 16:04:16], ~N[2015-01-01 16:04:16])
:eq
iex> Time.compare(~N[2015-01-01 16:04:16], ~N[2015-01-01 16:04:28])
:lt
iex> Time.compare(~N[2015-01-01 16:04:16.01], ~N[2000-01-01 16:04:16.001])
:gt
Link to this function convert(time, calendar) View Source
convert(Calendar.time, Calendar.calendar) ::
  {:ok, t} |
  {:error, atom}

Converts given time to a different calendar.

Returns {:ok, time} if the conversion was successful, or {:error, reason} if it was not, for some reason.

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> Time.convert(~T[13:30:15], Calendar.Holocene)
{:ok, %Time{calendar: Calendar.Holocene, hour: 13, minute: 30, second: 15, microsecond: {0, 0}}}

Similar to Time.convert/2, but raises an ArgumentError if the conversion between the two calendars is not possible.

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> Time.convert!(~T[13:30:15], Calendar.Holocene)
%Time{calendar: Calendar.Holocene, hour: 13, minute: 30, second: 15, microsecond: {0, 0}}
Link to this function diff(time1, time2, unit \\ :second) View Source

Returns the difference between two times, considering only the hour, minute second and microsecond.

As with the compare/2 function both Time structs and other structures containing time can be used. If for instance a NaiveDateTime or DateTime is passed, only the hour, month, second, and microsecond is considered. Any additional information about a date or time zone is ignored when calculating the difference.

The answer can be returned in any unit available from System.time_unit/0. If the first unit is smaller than the second, a negative number is returned.

This function returns the difference in seconds where seconds are measured according to Calendar.ISO.

Examples

iex> Time.diff(~T[00:29:12], ~T[00:29:10])
2

# When passing a [`NaiveDateTime`](NaiveDateTime.html) the date part is ignored.
iex> Time.diff(~N[2017-01-01 00:29:12], ~T[00:29:10])
2

# Two [`NaiveDateTime`](NaiveDateTime.html) structs could have big differences in the date
# but only the time part is considered.
iex> Time.diff(~N[2017-01-01 00:29:12], (~N[1900-02-03 00:29:10]))
2

iex> Time.diff(~T[00:29:12], ~T[00:29:10], :microsecond)
2_000_000
iex> Time.diff(~T[00:29:10], ~T[00:29:12], :microsecond)
-2_000_000
Link to this function from_erl(tuple, microsecond \\ {0, 0}, calendar \\ Calendar.ISO) View Source
from_erl(:calendar.time, Calendar.microsecond, Calendar.calendar) ::
  {:ok, t} |
  {:error, atom}

Converts an Erlang time tuple to a Time struct.

Examples

iex> Time.from_erl({23, 30, 15}, {5000, 3})
{:ok, ~T[23:30:15.005]}
iex> Time.from_erl({24, 30, 15})
{:error, :invalid_time}
Link to this function from_erl!(tuple, microsecond \\ {0, 0}, calendar \\ Calendar.ISO) View Source
from_erl!(:calendar.time, Calendar.microsecond, Calendar.calendar) :: t

Converts an Erlang time tuple to a Time struct.

Examples

iex> Time.from_erl!({23, 30, 15})
~T[23:30:15]
iex> Time.from_erl!({23, 30, 15}, {5000, 3})
~T[23:30:15.005]
iex> Time.from_erl!({24, 30, 15})
** (ArgumentError) cannot convert {24, 30, 15} to time, reason: :invalid_time
Link to this function from_iso8601(string, calendar \\ Calendar.ISO) View Source

Parses the extended “Local time” format described by ISO 8601:2004.

Timezone offset may be included in the string but they will be simply discarded as such information is not included in times.

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

Time representations with reduced accuracy are not supported.

Note that while ISO8601 allows times to specify 24:00:00 as the zero hour of the next day, this notation is not supported by Elixir.

Examples

iex> Time.from_iso8601("23:50:07")
{:ok, ~T[23:50:07]}
iex> Time.from_iso8601("23:50:07Z")
{:ok, ~T[23:50:07]}
iex> Time.from_iso8601("T23:50:07Z")
{:ok, ~T[23:50:07]}

iex> Time.from_iso8601("23:50:07,0123456")
{:ok, ~T[23:50:07.012345]}
iex> Time.from_iso8601("23:50:07.0123456")
{:ok, ~T[23:50:07.012345]}
iex> Time.from_iso8601("23:50:07.123Z")
{:ok, ~T[23:50:07.123]}

iex> Time.from_iso8601("2015:01:23 23-50-07")
{:error, :invalid_format}
iex> Time.from_iso8601("23:50:07A")
{:error, :invalid_format}
iex> Time.from_iso8601("23:50:07.")
{:error, :invalid_format}
iex> Time.from_iso8601("23:50:61")
{:error, :invalid_time}
Link to this function from_iso8601!(string) View Source
from_iso8601!(String.t) :: t

Parses the extended “Local time” format described by ISO 8601:2004.

Raises if the format is invalid.

Examples

iex> Time.from_iso8601!("23:50:07,123Z")
~T[23:50:07.123]
iex> Time.from_iso8601!("23:50:07.123Z")
~T[23:50:07.123]
iex> Time.from_iso8601!("2015:01:23 23-50-07")
** (ArgumentError) cannot parse "2015:01:23 23-50-07" as time, reason: :invalid_format
Link to this function new(hour, minute, second, microsecond \\ {0, 0}, calendar \\ Calendar.ISO) View Source

Builds a new time.

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

Note a time may have 60 seconds in case of leap seconds. Microseconds can also be given with a precision, which must be an integer between 0 and 6.

Examples

iex> Time.new(0, 0, 0, 0)
{:ok, ~T[00:00:00.000000]}
iex> Time.new(23, 59, 59, 999_999)
{:ok, ~T[23:59:59.999999]}
iex> Time.new(23, 59, 60, 999_999)
{:ok, ~T[23:59:60.999999]}

# Time with microseconds and their precision
iex> Time.new(23, 59, 60, {10_000, 2})
{:ok, ~T[23:59:60.01]}

iex> Time.new(24, 59, 59, 999_999)
{:error, :invalid_time}
iex> Time.new(23, 60, 59, 999_999)
{:error, :invalid_time}
iex> Time.new(23, 59, 61, 999_999)
{:error, :invalid_time}
iex> Time.new(23, 59, 59, 1_000_000)
{:error, :invalid_time}

# Invalid precision
Time.new(23, 59, 59, {999_999, 10})
{:error, :invalid_time}
Link to this function to_erl(time) View Source
to_erl(Calendar.time) :: :calendar.time

Converts given time to an Erlang time tuple.

WARNING: Loss of precision may occur, as Erlang time tuples only contain hours/minutes/seconds.

Examples

iex> Time.to_erl(~T[23:30:15.999])
{23, 30, 15}

iex> Time.to_erl(~N[2010-04-17 23:30:15.999])
{23, 30, 15}
Link to this function to_iso8601(time, format \\ :extended) View Source
to_iso8601(Calendar.time, :extended | :basic) :: String.t

Converts the given time to ISO 8601:2004.

By default, Time.to_iso8601/2 returns times formatted in the “extended” format, for human readability. It also supports the “basic” format through passing the :basic option.

Examples

iex> Time.to_iso8601(~T[23:00:13])
"23:00:13"

iex> Time.to_iso8601(~T[23:00:13.001])
"23:00:13.001"

iex> Time.to_iso8601(~T[23:00:13.001], :basic)
"230013.001"

iex> Time.to_iso8601(~N[2010-04-17 23:00:13])
"23:00:13"

Converts the given time to a string.

Examples

iex> Time.to_string(~T[23:00:00])
"23:00:00"
iex> Time.to_string(~T[23:00:00.001])
"23:00:00.001"
iex> Time.to_string(~T[23:00:00.123456])
"23:00:00.123456"

iex> Time.to_string(~N[2015-01-01 23:00:00.001])
"23:00:00.001"
iex> Time.to_string(~N[2015-01-01 23:00:00.123456])
"23:00:00.123456"
Link to this function utc_now(calendar \\ Calendar.ISO) View Source
utc_now(Calendar.calendar) :: t

Returns the current time in UTC.

Examples

iex> time = Time.utc_now()
iex> time.hour >= 0
true