2 # Copyright (c) 2005-2006 Philip Ross
4 # Permission is hereby granted, free of charge, to any person obtaining a copy
5 # of this software and associated documentation files (the "Software"), to deal
6 # in the Software without restriction, including without limitation the rights
7 # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8 # copies of the Software, and to permit persons to whom the Software is
9 # furnished to do so, subject to the following conditions:
11 # The above copyright notice and this permission notice shall be included in all
12 # copies or substantial portions of the Software.
14 # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15 # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16 # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
17 # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18 # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 require 'tzinfo/offset_rationals'
24 require 'tzinfo/time_or_datetime'
27 # A period of time in a timezone where the same offset from UTC applies.
29 # All the methods that take times accept instances of Time, DateTime or
32 # The TimezoneTransitionInfo that defines the start of this TimezonePeriod
33 # (may be nil if unbounded).
34 attr_reader
:start_transition
36 # The TimezoneTransitionInfo that defines the end of this TimezonePeriod
37 # (may be nil if unbounded).
38 attr_reader
:end_transition
40 # The TimezoneOffsetInfo for this period.
43 # Initializes a new TimezonePeriod.
44 def initialize(start_transition
, end_transition
, offset
= nil)
45 @start_transition = start_transition
46 @end_transition = end_transition
49 raise ArgumentError
, 'Offset specified with transitions' if @start_transition || @end_transition
53 @offset = @start_transition.offset
55 @offset = @end_transition.previous_offset
57 raise ArgumentError
, 'No offset specified and no transitions to determine it from'
61 @utc_total_offset_rational = nil
64 # Base offset of the timezone from UTC (seconds).
69 # Offset from the local time where daylight savings is in effect (seconds).
70 # E.g.: utc_offset could be -5 hours. Normally, std_offset would be 0.
71 # During daylight savings, std_offset would typically become +1 hours.
76 # The identifier of this period, e.g. "GMT" (Greenwich Mean Time) or "BST"
77 # (British Summer Time) for "Europe/London". The returned identifier is a
82 alias :zone_identifier :abbreviation
84 # Total offset from UTC (seconds). Equal to utc_offset + std_offset.
86 @offset.utc_total_offset
89 # Total offset from UTC (days). Result is a Rational.
90 def utc_total_offset_rational
91 unless @utc_total_offset_rational
92 @utc_total_offset_rational = OffsetRationals
.rational_for_offset(utc_total_offset
)
94 @utc_total_offset_rational
97 # The start time of the period in UTC as a DateTime. May be nil if unbounded.
99 @start_transition ? @start_transition.at
.to_datetime
: nil
102 # The end time of the period in UTC as a DateTime. May be nil if unbounded.
104 @end_transition ? @end_transition.at
.to_datetime
: nil
107 # The start time of the period in local time as a DateTime. May be nil if
110 @start_transition ? @start_transition.local_start
.to_datetime
: nil
113 # The end time of the period in local time as a DateTime. May be nil if
116 @end_transition ? @end_transition.local_end
.to_datetime
: nil
119 # true if daylight savings is in effect for this period; otherwise false.
124 # true if this period is valid for the given UTC DateTime; otherwise false.
125 def valid_for_utc
?(utc
)
126 utc_after_start
?(utc
) && utc_before_end
?(utc
)
129 # true if the given UTC DateTime is after the start of the period
130 # (inclusive); otherwise false.
131 def utc_after_start
?(utc
)
132 !@start_transition || @start_transition.at
<= utc
135 # true if the given UTC DateTime is before the end of the period
136 # (exclusive); otherwise false.
137 def utc_before_end
?(utc
)
138 !@end_transition || @end_transition.at
> utc
141 # true if this period is valid for the given local DateTime; otherwise false.
142 def valid_for_local
?(local
)
143 local_after_start
?(local
) && local_before_end
?(local
)
146 # true if the given local DateTime is after the start of the period
147 # (inclusive); otherwise false.
148 def local_after_start
?(local
)
149 !@start_transition || @start_transition.local_start
<= local
152 # true if the given local DateTime is before the end of the period
153 # (exclusive); otherwise false.
154 def local_before_end
?(local
)
155 !@end_transition || @end_transition.local_end
> local
158 # Converts a UTC DateTime to local time based on the offset of this period.
160 @offset.to_local(utc
)
163 # Converts a local DateTime to UTC based on the offset of this period.
165 @offset.to_utc(local
)
168 # Returns true if this TimezonePeriod is equal to p. This compares the
169 # start_transition, end_transition and offset using ==.
171 p
.respond_to
?(:start_transition) && p
.respond_to
?(:end_transition) &&
172 p
.respond_to
?(:offset) && start_transition
== p
.start_transition
&&
173 end_transition
== p
.end_transition
&& offset
== p
.offset
176 # Returns true if this TimezonePeriods is equal to p. This compares the
177 # start_transition, end_transition and offset using eql?
179 p
.respond_to
?(:start_transition) && p
.respond_to
?(:end_transition) &&
180 p
.respond_to
?(:offset) && start_transition
.eql
?(p
.start_transition
) &&
181 end_transition
.eql
?(p
.end_transition
) && offset
.eql
?(p
.offset
)
184 # Returns a hash of this TimezonePeriod.
186 result
= @start_transition.hash ^
@end_transition.hash
187 result ^
= @offset.hash
unless @start_transition || @end_transition
191 # Returns internal object state as a programmer-readable string.
193 result
= "#<#{self.class}: #{@start_transition.inspect},#{@end_transition.inspect}"
194 result
<< ",#{@offset.inspect}>" unless @start_transition || @end_transition