Chapter 12. Time Operations
A
Python program can handle time in several ways. Time intervals are
represented by floating-point numbers, in units of seconds (a
fraction of a second is the fractional part of the interval).
Particular instants in time are expressed in seconds since a
reference instant, known as the epoch.
(Midnight, UTC, of January 1, 1970, is a popular epoch used on both
Unix and Windows platforms.) Time instants often also need to be
expressed as a mixture of units of measurement (e.g., years, months,
days, hours, minutes, and seconds), particularly for I/O
purposes.
This chapter covers the time module, which
supplies Python's core time-handling functionality.
The time module strongly depends on the system C
library. The chapter also presents the sched and
calendar modules and the essentials of the popular
extension module mx.DateTime.
mx.DateTime has more uniform behavior across
platforms than time, which helps account for its
popularity.
Python 2.3 will introduce a new
datetime module to manipulate dates and times in
other ways. At http://starship.python.net/crew/jbauer/normaldate/,
you can download Jeff Bauer's
normalDate.py, which gains simplicity by dealing
only with dates, not with times. Neither of these modules is further
covered in this book.
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