ing to the system time zone database. If *dt* is naive (that is, dt.tzinfo is None), it is assumed to be in local time. In this case, a positive or zero value for *isdst* causes localtime to presume initially that summer time (for example, Daylight Saving Time) is or is not (respectively) in effect for the specified time. A negative value for *isdst* causes the localtime() function to attempt to divine whether summer time is in effect for the specified time. NrW