Timezones¶ ↑
Timezone Specifiers¶ ↑
Certain Time methods accept arguments that specify timezones:
-
Time.at: keyword argumentin:. -
Time.new: positional argumentzoneor keyword argumentin:. -
Time.now: keyword argumentin:. -
Time#getlocal: positional argumentzone. -
Time#localtime: positional argumentzone.
The value given with any of these must be one of the following (each detailed below):
Hours/Minutes Offsets¶ ↑
The zone value may be a string offset from UTC in the form '+HH:MM' or '-HH:MM', where:
-
HHis the 2-digit hour in the range0..23. -
MMis the 2-digit minute in the range0..59.
Examples:
t = Time.utc(2000, 1, 1, 20, 15, 1) # => 2000-01-01 20:15:01 UTC Time.at(t, in: '-23:59') # => 1999-12-31 20:16:01 -2359 Time.at(t, in: '+23:59') # => 2000-01-02 20:14:01 +2359
Single-Letter Offsets¶ ↑
The zone value may be a letter in the range 'A'..'I' or 'K'..'Z'; see List of military time zones:
t = Time.utc(2000, 1, 1, 20, 15, 1) # => 2000-01-01 20:15:01 UTC Time.at(t, in: 'A') # => 2000-01-01 21:15:01 +0100 Time.at(t, in: 'I') # => 2000-01-02 05:15:01 +0900 Time.at(t, in: 'K') # => 2000-01-02 06:15:01 +1000 Time.at(t, in: 'Y') # => 2000-01-01 08:15:01 -1200 Time.at(t, in: 'Z') # => 2000-01-01 20:15:01 UTC
Integer Offsets¶ ↑
The zone value may be an integer number of seconds in the range -86399..86399:
t = Time.utc(2000, 1, 1, 20, 15, 1) # => 2000-01-01 20:15:01 UTC Time.at(t, in: -86399) # => 1999-12-31 20:15:02 -235959 Time.at(t, in: 86399) # => 2000-01-02 20:15:00 +235959
Timezone Objects¶ ↑
In most cases, the zone value may be an object responding to certain timezone methods.
Exceptions (timezone object not allowed):
The timezone methods are:
-
local_to_utc:-
Called when
Time.newis invoked withtzas the value of positional argumentzoneor keyword argumentin:. -
Argument: a
Time::tmobject. -
Returns: a Time-like object in the UTC timezone.
-
-
utc_to_local:-
Called when
Time.atorTime.nowis invoked withtzas the value for keyword argumentin:, and whenTime#getlocalorTime#localtimeis called withtzas the value for positional argumentzone. -
Argument: a
Time::tmobject. -
Returns: a Time-like object in the local timezone.
-
A custom timezone class may have these instance methods, which will be called if defined:
-
abbr:-
Called when
Time#strftimeis invoked with a format involving%Z. -
Argument: a
Time::tmobject. -
Returns: a string abbreviation for the timezone name.
-
-
dst?:-
Called when
Time.atorTime.nowis invoked withtzas the value for keyword argumentin:, and whenTime#getlocalorTime#localtimeis called withtzas the value for positional argumentzone. -
Argument: a
Time::tmobject. -
Returns: whether the time is daylight saving time.
-
-
name:-
Called when <tt>Marshal.dump(t) is invoked
-
Argument: none.
-
Returns: the string name of the timezone.
-