Three or more bytes that are the designation for
the standard (std) and daylight savings time
(dst) timezones. Only std is required. If dst
is missing, then daylight savings time does not
apply in this locale. Upper- and lower-case
letters are allowed. Any characters except a
leading colon (:), digits, a comma (,), a minus
(-) or a plus (+) are allowed.
Indicates the value one must add to the local
time to arrive at Coordinated Universal Time.
The offset has the form:
The minutes (mm) and seconds (ss) are optional.
The hour (hh) is required and may be a single
digit. The offset following std is required.
If no offset follows dst , daylight savings time
is assumed to be one hour ahead of standard
time. One or more digits may be used; the value
is always interpreted as a decimal number. The
hour must be between 0 and 24, and the minutes
(and seconds) if present between 0 and 59. Out
of range values may cause unpredictable
behavior. If preceded by a "-" the timezone is
east of the Prime Meridian; otherwise it is west
(which may be indicated by an optional preceding
Indicate when to change to and back from daylight
savings time, where start/time describes
when the change from standard time to daylight
savings time occurs, and end/time describes when
the change back happens. Each time field
describes when, in current local time, the
change is made.
The formats of start and end are one of the following:
The Julian day n (1 < n < 365). Leap days
are not counted. That is, in all years,
February 28 is day 59 and March 1 is day
60. It is impossible to refer to the
occasional February 29.
The zero-based Julian day (0 < n < 365).
Leap days are counted, and it is possible
to refer to February 29.
The d**th day, (0 < d < 6) of week n of
month m of the year (1 < n < 5, 1 < m <
12), where week 5 means "the last d-day in
month m" which may occur in either the
fourth or the fifth week). Week 1 is the
first week in which the d**th day occurs.
Day zero is Sunday.
Implementation specific defaults are used for start
and end if these optional fields are not given.
The time has the same format as offset except
that no leading sign ("-" or "+") is allowed. The
default, if time is not given is 02:00:00.