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Diffstat (limited to 'doc')
-rw-r--r-- | doc/timezone_specifiers.rdoc | 46 | ||||
-rw-r--r-- | doc/timezones.rdoc | 108 |
2 files changed, 108 insertions, 46 deletions
diff --git a/doc/timezone_specifiers.rdoc b/doc/timezone_specifiers.rdoc deleted file mode 100644 index a6d57a1b21..0000000000 --- a/doc/timezone_specifiers.rdoc +++ /dev/null @@ -1,46 +0,0 @@ -=== Timezone Specifiers - -Certain methods in class Time accept arguments that specify timezones: - -- Time.at: keyword argument +in:+. -- Time.new: positional argument +zone+ or keyword argument +in:+. -- Time.now: keyword argument +in:+. -- Time#getlocal: positional argument +zone+. -- Time#localtime: positional argument +zone+. - -The value given with any of these must be one of the following: - -- A string offset from UTC in the form <tt>'+HH:MM'</tt> or <tt>-HH:MM</tt>, - where: - - - +HH+ is the 2-digit hour in the range <tt>0..23</tt>. - - +MM+ is the 2-digit minute in the range <tt>0..59</tt>. - - 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 - -- A letter in the range <tt>'A'..'I'</tt> or <tt>'K'..'Z'</tt>; - see {List of military time zones}[https://en.wikipedia.org/wiki/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 - -- An integer number of seconds in the range <tt>-86399..86399</tt>: - - 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 - --- -TODO: Pull in and revise the text at the link, -then add the example class TZ from the tests. -++ -- A timezone object; - see {Timezone Argument}[rdoc-ref:Time@Timezone+Argument] for details. diff --git a/doc/timezones.rdoc b/doc/timezones.rdoc new file mode 100644 index 0000000000..c3aae88fde --- /dev/null +++ b/doc/timezones.rdoc @@ -0,0 +1,108 @@ +== Timezones + +=== Timezone Specifiers + +Certain \Time methods accept arguments that specify timezones: + +- Time.at: keyword argument +in:+. +- Time.new: positional argument +zone+ or keyword argument +in:+. +- Time.now: keyword argument +in:+. +- Time#getlocal: positional argument +zone+. +- Time#localtime: positional argument +zone+. + +The value given with any of these must be one of the following +(each detailed below): + +- {Hours/minutes offset}[rdoc-ref:timezones.rdoc@Hours-2FMinutes+Offsets]. +- {Single-letter offset}[rdoc-ref:timezones.rdoc@Single-Letter+Offsets]. +- {Integer offset}[rdoc-ref:timezones.rdoc@Integer+Offsets]. +- {Timezone object}[rdoc-ref:timezones.rdoc@Timezone+Objects]. + +==== Hours/Minutes Offsets + +The zone value may be a string offset from UTC +in the form <tt>'+HH:MM'</tt> or <tt>'-HH:MM'</tt>, +where: + +- +HH+ is the 2-digit hour in the range <tt>0..23</tt>. +- +MM+ is the 2-digit minute in the range <tt>0..59</tt>. + +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 <tt>'A'..'I'</tt> +or <tt>'K'..'Z'</tt>; +see {List of military time zones}[https://en.wikipedia.org/wiki/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 <tt>-86399..86399</tt>: + + 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): + +- Time.new with positional argument +zone+. +- Time.now with keyword argument +in:+. + +The timezone methods are: + +- +local_to_utc+: + + - Called when Time.new is invoked with +tz+ + as the value of positional argument +zone+ or keyword argument +in:+. + - Argument: a <tt>Time::tm</tt> object. + - Returns: a \Time-like object in the UTC timezone. + +- +utc_to_local+: + + - Called when Time.at or Time.now is invoked with +tz+ + as the value for keyword argument +in:+, + and when Time#getlocal or Time#localtime is called with +tz+ + as the value for positional argument +zone+. + - Argument: a <tt>Time::tm</tt> object. + - 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#strftime is invoked with a format involving <tt>%Z</tt>. + - Argument: a <tt>Time::tm</tt> object. + - Returns: a string abbreviation for the timezone name. + +- +dst?+: + + - Called when Time.at or Time.now is invoked with +tz+ + as the value for keyword argument +in:+, + and when Time#getlocal or Time#localtime is called with +tz+ + as the value for positional argument +zone+. + - Argument: a <tt>Time::tm</tt> object. + - 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. |