Parses POSIX-style timezones:

Format

POSIX-style timezones are of the format: local_timezone,date/time,date/time

Where date is in the Mm.n.d format, and where:

• Mm (1-12) for 12 months
• n (1-5) 1 for the first week and 5 for the last week in the month
• d (0-6) 0 for Sunday and 6 for Saturday

Example

TZ = CST6CDT,M3.2.0/2:00:00,M11.1.0/2:00:00

This would represents a change to daylight saving time at 2:00 AM on the second Sunday in March and change back at 2:00 AM on the first Sunday in November, and keep 6 hours time offset from GMT every year. The breakdown of the string is:

• CST6CDT is the timezone name
• CST is the standard abbreviation
• 6 is the hours of time difference from GMT
• CDT is the DST abbreviation
• ,M3 is the third month
• .2 is the second occurrence of the day in the month
• .0 is Sunday
• /2:00:00 is the time
• ,M11 is the eleventh month
• .1 is the first occurrence of the day in the month
• .0 is Sunday
• /2:00:00 is the time