A TimeStamp is a floating point number expressing the time in seconds
since the Epoch at 1970-1-1.
We call this term a date-time structure. The first 5 fields are
integers expressing the year, month (1..12), day (1..31), hour (0..23)
and minute (0..59). The S field holds the seconds as a
floating point number between 0.0 and 60.0. Off is an integer
representing the offset relative to UTC in seconds, where positive
values are west of Greenwich. If converted from local time (see stamp_date_time/3),
TZ holds the name of the local timezone. If the timezone is
not known, TZ is the atom -. DST
is true if daylight saving time applies to the current
time, false if daylight saving time is relevant but not
effective, and - if unknown or the timezone
has no daylight saving time.