Older or stripped-down systems may support only the TZ values required by POSIX, which specify at most one start and end rule explicitly in the value. For example, TZ='EST5EDT,M3.2.0/02:00,M11.1.0/02:00' specifies time for the eastern United States starting in 2007. Such a TZ value must be changed whenever DST rules change, and the new value applies to all years, mishandling some older timestamps.
What does the TZ value EST5EDT,M3.2.0/02:00,M11.1.0/02:00 specify?
time for the eastern United States starting in 2007
For example, TZ='EST5EDT,M3.2.0/02:00,M11.1.0/02:00' specifies time for the eastern United States starting in 2007.
For example, TZ='ESTfiveEDT,Mthree point two.zero/two:zero,Meleven point one.zero/two:zero' specifies time for the eastern United States starting in two thousand seven.
What does the TZ value ESTfiveEDT,Mthree point two.zero/two:zero,Meleven point one.zero/two:zero specify?