class TZInfo::TimezonePeriod
{TimezonePeriod} represents a period of time for a time zone where the same offset from UTC applies. It provides access to the observed offset, time zone abbreviation, start time and end time.
The period of time can be unbounded at the start, end, or both the start and end.
@abstract Time zone period data will returned as an instance of one of the
subclasses of {TimezonePeriod}.
Attributes
@return [TimezoneOffset] the offset that applies in the period of time.
Public Class Methods
Initializes a {TimezonePeriod}.
@param offset [TimezoneOffset] the offset that is observed for the period
of time.
@raise [ArgumentError] if `offset` is `nil`.
# File lib/tzinfo/timezone_period.rb, line 21 def initialize(offset) raise ArgumentError, 'offset must be specified' unless offset @offset = offset end
Public Instance Methods
The abbreviation that identifies this offset. For example GMT (Greenwich Mean Time) or BST (British Summer Time) for Europe/London.
@return [String] the abbreviation that identifies this offset.
# File lib/tzinfo/timezone_period.rb, line 78 def abbreviation @offset.abbreviation end
Returns the base offset from UTC in seconds (`observed_utc_offset - #std_offset`). This does not include any adjustment made for daylight savings time and will typically remain constant throughout the year.
To obtain the currently observed offset from UTC, including the effect of daylight savings time, use {observed_utc_offset} instead.
If you require accurate {base_utc_offset} values, you should install the tzinfo-data gem and set {DataSources::RubyDataSource} as the {DataSource}. When using {DataSources::ZoneinfoDataSource}, the value of {base_utc_offset} has to be derived from changes to the observed UTC offset and DST status since it is not included in zoneinfo files.
@return [Integer] the base offset from UTC in seconds.
# File lib/tzinfo/timezone_period.rb, line 52 def base_utc_offset @offset.base_utc_offset end
Determines if daylight savings is in effect (i.e. if {std_offset} is non-zero).
@return [Boolean] `true` if {std_offset} is non-zero, otherwise `false`.
# File lib/tzinfo/timezone_period.rb, line 97 def dst? @offset.dst? end
@return [TimezoneTransition] the transition that defines the end of this
{TimezonePeriod} (`nil` if the end is unbounded).
# File lib/tzinfo/timezone_period.rb, line 34 def end_transition raise_not_implemented(:end_transition) end
Returns the UTC end time of the period or `nil` if the end of the period is unbounded.
The result is returned as a {Timestamp}. To obtain the end time as a `Time` or `DateTime`, call either {Timestamp#to_time to_time} or {Timestamp#to_datetime to_datetime} on the result.
@return [Timestamp] the UTC end time of the period or `nil` if the end of
the period is unbounded.
# File lib/tzinfo/timezone_period.rb, line 123 def ends_at timestamp(end_transition) end
Returns the local end time of the period or `nil` if the end of the period is unbounded.
The result is returned as a {TimestampWithOffset}. To obtain the end time as a `Time` or `DateTime`, call either {TimestampWithOffset#to_time to_time} or {TimestampWithOffset#to_datetime to_datetime} on the result.
@return [TimestampWithOffset] the local end time of the period or `nil` if
the end of the period is unbounded.
# File lib/tzinfo/timezone_period.rb, line 149 def local_ends_at timestamp_with_offset(end_transition) end
Returns the local start time of the period or `nil` if the start of the period is unbounded.
The result is returned as a {TimestampWithOffset}. To obtain the start time as a `Time` or `DateTime`, call either {TimestampWithOffset#to_time to_time} or {TimestampWithOffset#to_datetime to_datetime} on the result.
@return [TimestampWithOffset] the local start time of the period or `nil`
if the start of the period is unbounded.
# File lib/tzinfo/timezone_period.rb, line 136 def local_starts_at timestamp_with_offset(start_transition) end
Returns the observed offset from UTC in seconds (`base_utc_offset + #std_offset`). This includes adjustments made for daylight savings time.
@return [Integer] the observed offset from UTC in seconds.
# File lib/tzinfo/timezone_period.rb, line 88 def observed_utc_offset @offset.observed_utc_offset end
@return [TimezoneTransition] the transition that defines the start of this
{TimezonePeriod} (`nil` if the start is unbounded).
# File lib/tzinfo/timezone_period.rb, line 28 def start_transition raise_not_implemented(:start_transition) end
Returns the UTC start time of the period or `nil` if the start of the period is unbounded.
The result is returned as a {Timestamp}. To obtain the start time as a `Time` or `DateTime`, call either {Timestamp#to_time to_time} or {Timestamp#to_datetime to_datetime} on the result.
@return [Timestamp] the UTC start time of the period or `nil` if the start
of the period is unbounded.
# File lib/tzinfo/timezone_period.rb, line 110 def starts_at timestamp(start_transition) end
Returns the offset from the time zone's standard time in seconds (`observed_utc_offset - #base_utc_offset`). Zero when daylight savings time is not in effect. Non-zero (usually 3600 = 1 hour) if daylight savings is being observed.
If you require accurate {std_offset} values, you should install the tzinfo-data gem and set {DataSources::RubyDataSource} as the {DataSource}. When using {DataSources::ZoneinfoDataSource}, the value of {std_offset} has to be derived from changes to the observed UTC offset and DST status since it is not included in zoneinfo files.
@return [Integer] the offset from the time zone's standard time in
seconds.
# File lib/tzinfo/timezone_period.rb, line 70 def std_offset @offset.std_offset end
Private Instance Methods
Raises a {NotImplementedError} to indicate that subclasses should override a method.
@raise [NotImplementedError] always.
# File lib/tzinfo/timezone_period.rb, line 159 def raise_not_implemented(method_name) raise NotImplementedError, "Subclasses must override #{method_name}" end
@param transition [TimezoneTransition] a transition or `nil`. @return [Timestamp] the {Timestamp} representing when a transition occurs,
or `nil` if `transition` is `nil`.
# File lib/tzinfo/timezone_period.rb, line 166 def timestamp(transition) transition ? transition.at : nil end
@param transition [TimezoneTransition] a transition or `nil`. @return [TimestampWithOffset] a {Timestamp} representing when a transition
occurs with offset set to {#offset}, or `nil` if `transition` is `nil`.
# File lib/tzinfo/timezone_period.rb, line 173 def timestamp_with_offset(transition) transition ? TimestampWithOffset.set_timezone_offset(transition.at, offset) : nil end