define backward-zones
Africa/Asmera
Africa/Timbuktu
America/Argentina/ComodRivadavia
America/Atka
America/Buenos_Aires
America/Catamarca
America/Coral_Harbour
America/Cordoba
America/Ensenada
America/Fort_Wayne
America/Indianapolis
America/Jujuy
America/Knox_IN
America/Louisville
America/Mendoza
America/Porto_Acre
America/Rosario
America/Virgin
Asia/Ashkhabad
Asia/Chungking
Asia/Dacca
Asia/Katmandu
Asia/Calcutta
Asia/Macao
Asia/Tel_Aviv
Asia/Saigon
Asia/Thimbu
Asia/Ujung_Pandang
Asia/Ulan_Bator
Atlantic/Faeroe
Atlantic/Jan_Mayen
Australia/ACT
Australia/Canberra
Australia/LHI
Australia/NSW
Australia/North
Australia/Queensland
Australia/South
Australia/Tasmania
Australia/Victoria
Australia/West
Australia/Yancowinna
Brazil/Acre
Brazil/DeNoronha
Brazil/East
Brazil/West
Canada/Atlantic
Canada/Central
Canada/East-Saskatchewan
Canada/Eastern
Canada/Mountain
Canada/Newfoundland
Canada/Pacific
Canada/Saskatchewan
Canada/Yukon
Chile/Continental
Chile/EasterIsland
Cuba
Egypt
Eire
Europe/Belfast
Europe/Tiraspol
GB
GB-Eire
GMT+0
GMT-0
GMT0
Greenwich
Hongkong
Iceland
Iran
Israel
Jamaica
Japan
Kwajalein
Libya
Mexico/BajaNorte
Mexico/BajaSur
Mexico/General
NZ
NZ-CHAT
Navajo
PRC
Pacific/Samoa
Pacific/Yap
Poland
Portugal
ROC
ROK
Singapore
Turkey
UCT
US/Alaska
US/Aleutian
US/Arizona
US/Central
US/East-Indiana
US/Eastern
US/Hawaii
US/Indiana-Starke
US/Michigan
US/Mountain
US/Pacific
US/Samoa
UTC
Universal
W-SU
Zulu
endef
backward-zones := $(subst $(nl), ,$(backward-zones))
ifdef backward-zones
$(addprefix $(inst_zonedir)/right/,$(backward-zones)): \
$(foreach t,$(tzbases),$(addprefix $(inst_zonedir)/right/,$($t-zones)))
$(addprefix $(inst_zonedir)/posix/,$(backward-zones)): \
$(foreach t,$(tzbases),$(addprefix $(inst_zonedir)/posix/,$($t-zones)))
$(addprefix $(inst_zonedir)/,$(backward-zones)): \
$(foreach t,$(tzbases),$(addprefix $(inst_zonedir)/,$($t-zones)))
$(addprefix $(dir $(inst_zonedir))zone%/right/,$(backward-zones)): \
backward $(objpfx)zic leapseconds yearistype
	$(tzcompile)
$(addprefix $(dir $(inst_zonedir))zone%/posix/,$(backward-zones)): \
backward $(objpfx)zic /dev/null yearistype
	$(tzcompile)
$(addprefix $(dir $(inst_zonedir))zone%/,$(backward-zones)): \
backward $(objpfx)zic $(leapseconds) yearistype
	$(tzcompile)
endif
zonenames := $(zonenames) $(backward-zones)