@spec add(Calendar.time(), integer(), :hour | :minute | System.time_unit()) :: t()

Adds the amount_to_add of units to the given time.

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.

Note the result value represents the time of day, meaning that it is cyclic, for instance, it will never go over 24 hours for the ISO calendar.

Examples

iex> Time.add(~T[10:00:00], 27000)
~T[17:30:00]
iex> Time.add(~T[11:00:00.005], 2400)
~T[11:40:00.005]
iex> Time.add(~T[00:00:00.000], 86_399_999, :millisecond)
~T[23:59:59.999]

Negative values are allowed:

iex> Time.add(~T[23:00:00], -60)
~T[22:59:00]

Note that the time is cyclic:

iex> Time.add(~T[17:10:05], 86400)
~T[17:10:05]

Hours and minutes are also supported:

iex> Time.add(~T[17:10:05], 2, :hour)
~T[19:10:05]
iex> Time.add(~T[17:10:05], 30, :minute)
~T[17:40:05]

This operation merges the precision of the time with the given unit:

iex> result = Time.add(~T[00:29:10], 21, :millisecond)
~T[00:29:10.021]
iex> result.microsecond
{21000, 3}

@spec 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

@spec 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}}}

@spec convert!(Calendar.time(), Calendar.calendar()) :: t()

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}}

@spec diff(Calendar.time(), Calendar.time(), :hour | :minute | System.time_unit()) ::
  integer()

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, minute, 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 :hour, :minute, :second or any subsecond unit available from System.time_unit/0. If the first time value is earlier than the second, a negative number is returned.

The unit is measured according to Calendar.ISO and defaults to :second. Fractional results are not supported and are truncated.

Examples

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

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

# Two `NaiveDateTime` 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

iex> Time.diff(~T[02:29:10], ~T[00:29:10], :hour)
2
iex> Time.diff(~T[02:29:10], ~T[00:29:11], :hour)
1

@spec 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}

@spec 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

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

Parses the extended "Local time" 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 times.

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

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}

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

Parses the extended "Local time" format described by ISO 8601:2019.

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

@spec from_seconds_after_midnight(
  integer(),
  Calendar.microsecond(),
  Calendar.calendar()
) :: t()

Converts a number of seconds after midnight to a Time struct.

Examples

iex> Time.from_seconds_after_midnight(10_000)
~T[02:46:40]
iex> Time.from_seconds_after_midnight(30_000, {5000, 3})
~T[08:20:00.005]
iex> Time.from_seconds_after_midnight(-1)
~T[23:59:59]
iex> Time.from_seconds_after_midnight(100_000)
~T[03:46:40]

@spec new(
  Calendar.hour(),
  Calendar.minute(),
  Calendar.second(),
  Calendar.microsecond() | non_neg_integer(),
  Calendar.calendar()
) :: {:ok, t()} | {:error, atom()}

Builds a new time.

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

Microseconds can also be given with a precision, which must be an integer between 0 and 6.

The built-in calendar does not support leap seconds.

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

@spec new!(
  Calendar.hour(),
  Calendar.minute(),
  Calendar.second(),
  Calendar.microsecond() | non_neg_integer(),
  Calendar.calendar()
) :: t()

Builds a new time.

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

Microseconds can also be given with a precision, which must be an integer between 0 and 6.

The built-in calendar does not support leap seconds.

Examples

iex> Time.new!(0, 0, 0, 0)
~T[00:00:00.000000]
iex> Time.new!(23, 59, 59, 999_999)
~T[23:59:59.999999]
iex> Time.new!(24, 59, 59, 999_999)
** (ArgumentError) cannot build time, reason: :invalid_time

@spec 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}

@spec to_iso8601(Calendar.time(), :extended | :basic) :: String.t()

Converts the given time to ISO 8601:2019.

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"

@spec to_seconds_after_midnight(Calendar.time()) :: {integer(), non_neg_integer()}

Converts a Time struct to a number of seconds after midnight.

The returned value is a two-element tuple with the number of seconds and microseconds.

Examples

iex> Time.to_seconds_after_midnight(~T[23:30:15])
{84615, 0}
iex> Time.to_seconds_after_midnight(~N[2010-04-17 23:30:15.999])
{84615, 999000}

@spec to_string(Calendar.time()) :: String.t()

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"

@spec truncate(t(), :microsecond | :millisecond | :second) :: t()

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

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

Examples

iex> Time.truncate(~T[01:01:01.123456], :microsecond)
~T[01:01:01.123456]

iex> Time.truncate(~T[01:01:01.123456], :millisecond)
~T[01:01:01.123]

iex> Time.truncate(~T[01:01:01.123456], :second)
~T[01:01:01]

@spec utc_now(Calendar.calendar()) :: t()

Returns the current time in UTC.

Examples

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