Class: TimeWithZone

Inherits:
Object
  • Object
show all
Defined in:
lib/time_with_zone.rb,
lib/time_with_zone/version.rb

Overview

Handle time with zone withtout ActiveSupport or ENV

require 'time_with_zone'

TimeWithZone.strptime_with_zone('2016-10-10', '%Y-%m-%d', 'Asia/Taipei')
# => '2016-10-10 00:00:00 +0800'

TimeWithZone.parse_with_zone('2016-10-10', 'Asia/Taipei')
# => '2016-10-10 00:00:00 +0800'

time = Time.parse('2016-10-10 00:00:00 +00:00')
TimeWithZone.set_zone!(time, 'Asia/Taipei')
# => '2016-10-10 00:00:00 +0800'

time = Time.parse('2016-10-10 00:00:00 +00:00')
TimeWithZone.localtime_with_zone(time, 'Asia/Taipei')
# => '2016-10-10 08:00:00 +0800'

Constant Summary collapse

NUMERIC_PATTERN =

[+-]HH:MM, [+-]HHMM, [+-]HH

%r{\A[+-]\d\d(:?\d\d)?\z}
NAME_PATTERN =

Region/Zone, Region/Zone/Zone

%r{\A[^/]+/[^/]+(/[^/]+)?\z}
ZoneOffset =

Short-abbreviation timezone which Ruby’s Time class supports

See Also:

(class << Time; self; end)::ZoneOffset
VERSION = 
"0.2.0"

Class Method Summary collapse

Class Method Details

.localtime_with_zone(time, timezone) ⇒ Object

Time#localtime with timezone (non-destructive)

ENV['TZ'] = '+09:00' # Assume your local timezone is +09:00

require 'time'

time = Time.parse("2016-10-20 00:00:00 +00:00") 
time.dup.localtime("+08:00")
#=> 2010-10-20 08:00:00 +0800
time.dump.localtime("CDT")
#=> error
time.dump.localtime("Asia/Taipei")
#=> error

require 'time_with_zone'

time = Time.parse("2016-10-20 00:00:00 +00:00") 
TimeWithZone.localtime_with_zone(time, "+08:00")
#=> 2010-10-20 08:00:00 +0800
TimeWithZone.localtime_with_zone(time, "CDT")
#=> 2016-10-19 19:00:00 -0500
TimeWithZone.localtime_with_zone(time, "Asia/Taipei")
#=> 2010-10-20 08:00:00 +0800

Parameters:



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# File 'lib/time_with_zone.rb', line 61

def self.localtime_with_zone(time, timezone)
  localtime_with_zone!(time.dup, timezone)
end

.localtime_with_zone!(time, timezone) ⇒ Object

Time#localtime with timezone (destructive)

Parameters:

See Also:



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# File 'lib/time_with_zone.rb', line 70

def self.localtime_with_zone!(time, timezone)
  _zone_offset = zone_offset(timezone, time)
  time.localtime(_zone_offset)
end

.parse_with_zone(date, timezone) ⇒ Object

Time.parse with timezone

ENV['TZ'] = '+09:00' # Assume your local timezone is +09:00

require 'time'

Time.parse("2016-10-20")
#=> 2016-10-20 00:00:00 +0900
Time.parse("2016-10-20 00:00:00 +08:00")
#=> 2016-10-20 00:00:00 +0800
Time.parse("2016-10-20 00:00:00 CDT")
#=> 2016-10-20 00:00:00 -0500
Time.parse("2016-10-20 00:00:00 Asia/Taipei")
#=> 2016-10-20 00:00:00 +0900 (does not work)

require 'time_with_zone'

TimeWithZone.parse_with_zone("2016-10-20", "+08:00")
#=> 2016-10-20 00:00:00 +0800
TimeWithZone.parse_with_zone("2016-10-20", "CDT")
#=> 2016-10-20 00:00:00 -0500
TimeWithZone.parse_with_zone("2016-10-20", "Asia/Taipei")
#=> 2016-10-20 00:00:00 +0800

Parameters:



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# File 'lib/time_with_zone.rb', line 101

def self.parse_with_zone(date, timezone)
  time = Time.parse(date)
  set_zone!(time, timezone)
end

.set_zone(time, timezone) ⇒ Time

This method simply sets the zone field of Time object (non-destructive)

require 'time_with_zone'

time = Time.parse("2016-02-02 00:00:00 +00:00")
TimeWithZone.set_zone(time, "+08:00")
#=> "2016-02-02 00:00:00 +0800"
# Note that it is not "2016-02-02 08:00:00 +0800" like Time#localtime(timezone)

Parameters:

  • time (Time)
  • timezone (String)

Returns:

  • (Time) 


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# File 'lib/time_with_zone.rb', line 150

def self.set_zone(time, timezone)
  set_zone!(time.dup, timezone)
end

.set_zone!(time, timezone) ⇒ Object

This method simply sets the zone field of Time object (destructive)

Parameters:

  • time (Time)
  • timezone (String)

See Also:



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# File 'lib/time_with_zone.rb', line 159

def self.set_zone!(time, timezone)
  _utc_offset = time.utc_offset
  _zone_offset = zone_offset(timezone, time)
  time.localtime(_zone_offset) + _utc_offset - _zone_offset
end

.strptime_with_zone(date, format, timezone) ⇒ Object

Time.strptime with timezone

ENV['TZ'] = '+09:00' # Assume your local timezone is +09:00

require 'time'

Time.strptime("2016-10-20", "%Y-%m-%d")
#=> 2016-10-20 00:00:00 +0900
Time.strptime("2016-10-20 +08:00", "%Y-%m-%d %z")
#=> 2016-10-20 00:00:00 +0800
Time.strptime("2016-10-20 CDT", "%Y-%m-%d %Z")
#=> 2016-10-20 00:00:00 -0500
Time.strptime("2016-10-20 Asia/Taipei", "%Y-%m-%d %Z")
#=> 2016-10-20 00:00:00 +0900 (does not work)

require 'time_with_zone'

TimeWithZone.strptime_with_zone("2016-10-20", "%Y-%m-%d", "+08:00")
#=> 2016-10-20 00:00:00 +0800
TimeWithZone.strptime_with_zone("2016-10-20", "%Y-%m-%d", "CDT")
#=> 2016-10-20 00:00:00 -0500
TimeWithZone.strptime_with_zone("2016-10-20", "%Y-%m-%d", "Asia/Taipei")
#=> 2016-10-20 00:00:00 +0800

Parameters:



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# File 'lib/time_with_zone.rb', line 133

def self.strptime_with_zone(date, format, timezone)
  time = Time.strptime(date, format)
  set_zone!(time, timezone)
end

.zone_offset(timezone, time = nil) ⇒ Integer

Returns zone offset for given timezone string

require 'time_with_zone'

TimeWithZone.zone_offset("+08:00")
#=> 28800
TimeWithZone.zone_offset("Asia/Taipei")
#=> 28800
TimeWithZone.zone_offset("PST")
#=> -28800
TimeWithZone.zone_offset("America/Los_Angeles")
#=> -25200 
TimeWithZone.zone_offset("America/Los_Angeles", Time.parse("2016-07-07 00:00:00 +00:00"))
#=> -25200 # DST (Daylight Saving Time)
TimeWithZone.zone_offset("America/Los_Angeles", Time.parse("2016-01-01 00:00:00 +00:00"))
#=> -28800 # non DST

Parameters:

Returns:

  • (Integer) —

    zone offset



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# File 'lib/time_with_zone.rb', line 185

def self.zone_offset(timezone, time = nil)
  if NUMERIC_PATTERN === timezone
    Time.zone_offset(timezone)
  elsif NAME_PATTERN === timezone
    tz = TZInfo::Timezone.get(timezone)
    if time
      tz.period_for_utc(time).utc_total_offset
    else
      tz.current_period.utc_total_offset
    end
  elsif ZoneOffset.include?(timezone)
    ZoneOffset[timezone] * 3600
  else
    raise ArgumentError, "timezone format is invalid: #{timezone}"
  end
end