All relevant timezone information for a given period, i.e. Europe/Moscow on March 3rd, 2013

Notes:

• full_name is the name of the zone, but does not indicate anything about the current period (i.e. CST vs CDT)
• abbreviation is the abbreviated name for the zone in the current period, i.e. “America/Chicago” on 3/30/15 is “CDT”
• offset_std is the offset in minutes from standard time for this period
• offset_utc is the offset in minutes from UTC for this period Spec:
• day_of_week: :sunday, :monday, :tuesday, etc
• datetime: {{year, month, day}, {hour, minute, second}}
• from: :min | :max | {day_of_week, datetime}, when this zone starts
• until: :min | :max | {day_of_week, datetime}, when this zone ends