Read this: 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.
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): 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