Chapter 10. Dates and Times
Dates and times are important to many ActionScript applications, particularly when you develop more robust applications that offer users services. Date and time values are important for determining the amount of time that has elapsed for timed operations, for determining whether a user’s trial membership is active, and for storing transaction dates, to name but a few scenarios.
ActionScript stores dates and
milliseconds, which are the number of milliseconds that
have elapsed since the
Epoch, namely midnight,
January 1, 1970 Coordinated Universal Time (UTC). For our purposes,
UTC is essentially equivalent to the
more familiar Greenwich Mean Time (GMT).
(See http://aa.usno.navy.mil/faq/docs/UT.html to
learn about the subtle distinctions.) Many programming languages
store dates in terms of the Epoch (often in seconds instead of
milliseconds); therefore, you can readily work with date and time
values that have been imported from other sources (and vice versa).
In addition, the
Date class allows
to set and get date and time values in terms of years, months, days,
and so on,
using methods such as
getMonth( ), and
). These methods are for your convenience, but the values
are stored internally as Epoch milliseconds.