Zone Language - Rules

• We're in Unix world - lets do it in a text file with rules:

  Rule  US    1967  1973  -     Apr  lastSun  2:00  1:00  D
  

• This rule is part of the 'US' rules family.
• It applies to times between years 1967-1973, inclusive.
• It applies to all years in this range (the '-' states that).
• The rule takes effect on the last Sunday of April, on 2AM.
• At which time we should add 1:00 hours to the local-time,
• And we then change the variable-part of the abbreviation of the time-zone to 'D'.

Originally written by guy keren