org.embulk.util.rubytime

Class RubyTimeZones

java.lang.Object

org.embulk.util.rubytime.RubyTimeZones

public final class RubyTimeZones
extends Object

This class contains a static method to interpret a timezone string in the manner of Ruby's Time class.

Ruby's Date and DateTime classes accept a superset of timezone strings which are accepted by Ruby's Time class. Ruby's Time.strptime internally calls Date._strptime just to expand a date-time string into elements, and then resolves the expanded elements by Time's own way. In other words, some timezone strings are recognized once by Date._strptime at first, and then by Time.strptime ignores them.

For example, Date recognizes "CEST" although Time does not recognize it. On the other hand, both recognizes "PST".

 $ env TZ=UTC irb
 irb(main):001:0> require 'date'
 => true
 irb(main):002:0> require 'time'
 => true

 irb(main):003:0> Date._strptime("CEST", "%z")
 => {:zone=>"CEST", :offset=>7200}

 irb(main):004:0> DateTime.strptime("2017-12-31 12:34:56 CEST", "%Y-%m-%d %H:%M:%S %z")
 => #<DateTime: 2017-12-31T12:34:56+02:00 ((2458119j,38096s,0n),+7200s,2299161j)>

 irb(main):005:0> Time.strptime("2017-12-31 12:34:56 CEST", "%Y-%m-%d %H:%M:%S %z")
 => 2017-12-31 12:34:56 +0000

 irb(main):006:0> Date._strptime("PST", "%z")
 => {:zone=>"PST", :offset=>-28800}

 irb(main):007:0> DateTime.strptime("2017-12-31 12:34:56 PST", "%Y-%m-%d %H:%M:%S %z")
 => #<DateTime: 2017-12-31T12:34:56-08:00 ((2458119j,74096s,0n),-28800s,2299161j)>

 irb(main):008:0> Time.strptime("2017-12-31 12:34:56 PST", "%Y-%m-%d %H:%M:%S %z")
 => 2017-12-31 12:34:56 -0800

Method Summary

Modifier and Type	Method and Description
static ZoneOffset	toZoneOffset(String zoneName, ZoneOffset defaultZoneOffset) Converts a timezone string into ZoneOffset in the manner of Ruby's Time class.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

toZoneOffset

public static ZoneOffset toZoneOffset(String zoneName,
                                      ZoneOffset defaultZoneOffset)

Converts a timezone string into ZoneOffset in the manner of Ruby's Time class.

Note that it has a difference from Ruby Time.strptime, where it does not consider the local timezone. It returns defaultZoneOffset if the given timezone string is invalid -- neither numerical nor predefined textual timezone names. In contrast, Ruby's Time.strptime considers the local timezone in that case.

Parameters:

zoneName - a timezone string

defaultZoneOffset - a ZoneOffset for default

Returns:

a ZoneOffset converted

See Also:

zone_offset in Ruby