operating system services operation description td td td <td td =td td !td td td td >td comparison here are some examplestoday datetime datetime now(today ctime('thu oct : : oneday datetime timedelta(days= tomorrow today oneday tomorrow ctime('fri oct : : in addition to these operationsall datedatetimetimeand timedelta objects are immutable this means that they can be used as dictionary keysplaced in setsand used in variety of other operations tzinfo objects many of the methods in the datetime module manipulate special tzinfo objects that represent information about time zone tzinfo is merely base class individual time zones are created by inheriting from tzinfo and implementing the following methodstz dst(dtreturns timedelta object representing daylight savings time adjustmentsif applicable returns none if no information is known about dst the argument dt is either datetime object or none tz fromutc(dtconverts datetime objectdtfrom utc time to the local time zone and returns new datetime object this method is called by the astimezone(method on datetime objects default implementation is already provided by tzinfoso it' usually not necessary to redefine this method tz tzname(dtreturns string with the name of the time zone (for example"us/central"dt is either datetime object or none tz utcoffset(dtreturns timedelta object representing the offset of local time from utc in minutes east of utc the offset incorporates all elements that make up the local timeincluding daylight savings timeif applicable the argument dt is either datetime object or none lib fl ff