Time — Elixir v1.18.3 (original) (raw)

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 (see sigil_T/2) 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 expectCalendar.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 third-party calendar libraries.

Comparing times

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

iex> Enum.min([~T[23:00:07.001], ~T[10:00:07.001]], Time)
~T[10:00:07.001]

Summary

Functions

Adds the amount_to_add of units to the given time.

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

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

Compares two time structs.

Converts given time to a different calendar.

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

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

Converts an Erlang time tuple to a Time struct.

Converts an Erlang time tuple to a Time struct.

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

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

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

Shifts given time by duration according to its calendar.

Converts given time to an Erlang time tuple.

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

Converts the given time to a string.

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

Returns the current time in UTC.

Types

Functions

Adds the amount_to_add of units to the given time.

Accepts an amount_to_add in any unit. unit can be:hour, :minute, :second or any subsecond precision fromSystem.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}

To shift a time by a Duration and according to its underlying calendar, use Time.shift/2.

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

Examples

iex> Time.after?(~T[16:04:28], ~T[16:04:16])
true
iex> Time.after?(~T[16:04:16], ~T[16:04:16])
false
iex> Time.after?(~T[16:04:16.001], ~T[16:04:16.01])
false

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

Examples

iex> Time.before?(~T[16:04:16], ~T[16:04:28])
true
iex> Time.before?(~T[16:04:16], ~T[16:04:16])
false
iex> Time.before?(~T[16:04:16.01], ~T[16:04:16.001])
false

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

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 ArgumentErrorif 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}}

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 DateTimeis 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

Converts an Erlang time tuple to a Time struct.

Examples

iex> Time.from_erl({23, 30, 15})
{:ok, ~T[23:30:15]}
iex> Time.from_erl({23, 30, 15}, 5000)
{:ok, ~T[23:30:15.005000]}
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}

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)
~T[23:30:15.005000]
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

Parses the extended "Local time" format described byISO 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}

Parses the extended "Local time" format described byISO 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

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]

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}

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

Shifts given time by duration according to its calendar.

Available duration units are: :hour, :minute, :second, :microsecond.

When using the default ISO calendar, durations are collapsed to seconds and microseconds before they are applied.

Raises an ArgumentError when called with date scale units.

Examples

iex> Time.shift(~T[01:00:15], hour: 12)
~T[13:00:15]
iex> Time.shift(~T[01:35:00], hour: 6, minute: -15)
~T[07:20:00]
iex> Time.shift(~T[01:15:00], second: 125)
~T[01:17:05]
iex> Time.shift(~T[01:00:15], microsecond: {100, 6})
~T[01:00:15.000100]
iex> Time.shift(~T[01:15:00], Duration.new!(second: 65))
~T[01:16:05]

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}

Converts the given time toISO 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"

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}

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]

Returns the current time in UTC.

Examples

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