isdst

Returns true if time occurs during Daylight Saving Time in its time zone.

# CST6CDT:

Time.local(2000, 1, 1).zone    #=> "CST"
Time.local(2000, 1, 1).isdst   #=> false
Time.local(2000, 1, 1).dst?    #=> false
Time.local(2000, 7, 1).zone    #=> "CDT"
Time.local(2000, 7, 1).isdst   #=> true
Time.local(2000, 7, 1).dst?    #=> true

# Asia/Tokyo:

Time.local(2000, 1, 1).zone    #=> "JST"
Time.local(2000, 1, 1).isdst   #=> false
Time.local(2000, 1, 1).dst?    #=> false
Time.local(2000, 7, 1).zone    #=> "JST"
Time.local(2000, 7, 1).isdst   #=> false
Time.local(2000, 7, 1).dst?    #=> false