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# This file is in the public domain, so clarified as of 
# 2009-05-17 by Arthur David Olson. 
 
# Old rules, should the need arise. 
# No attempt is made to handle Newfoundland, since it cannot be expressed 
# using the System V "TZ" scheme (half-hour offset), or anything outside 
# North America (no support for non-standard DST start/end dates), nor 
# the changes in the DST rules in the US after 1976 (which occurred after 
# the old rules were written). 
# 
# If you need the old rules, uncomment ## lines. 
# Compile this *without* leap second correction for true conformance. 
 
# Rule  NAME    FROM    TO      TYPE    IN      ON      AT      SAVE    LETTER/S 
Rule    SystemV min     1973    -       Apr     lastSun 2:00    1:00    D 
Rule    SystemV min     1973    -       Oct     lastSun 2:00    0       S 
Rule    SystemV 1974    only    -       Jan     6       2:00    1:00    D 
Rule    SystemV 1974    only    -       Nov     lastSun 2:00    0       S 
Rule    SystemV 1975    only    -       Feb     23      2:00    1:00    D 
Rule    SystemV 1975    only    -       Oct     lastSun 2:00    0       S 
Rule    SystemV 1976    max     -       Apr     lastSun 2:00    1:00    D 
Rule    SystemV 1976    max     -       Oct     lastSun 2:00    0       S 
 
# Zone  NAME            GMTOFF  RULES/SAVE      FORMAT  [UNTIL] 
## Zone SystemV/AST4ADT -4:00   SystemV         A%sT 
## Zone SystemV/EST5EDT -5:00   SystemV         E%sT 
## Zone SystemV/CST6CDT -6:00   SystemV         C%sT 
## Zone SystemV/MST7MDT -7:00   SystemV         M%sT 
## Zone SystemV/PST8PDT -8:00   SystemV         P%sT 
## Zone SystemV/YST9YDT -9:00   SystemV         Y%sT 
## Zone SystemV/AST4    -4:00   -               AST 
## Zone SystemV/EST5    -5:00   -               EST 
## Zone SystemV/CST6    -6:00   -               CST 
## Zone SystemV/MST7    -7:00   -               MST 
## Zone SystemV/PST8    -8:00   -               PST 
## Zone SystemV/YST9    -9:00   -               YST 
## Zone SystemV/HST10   -10:00  -               HST