Readers, For a 12 hour time stamp: > testtime<-("2013-01-01 01:00:01 PM") > testtime [1] "2013-01-01 01:00:01 PM" > testtime24hour<-strftime(testtime,'%H:%M:%S') > testtime24hour [1] "01:00:01" how to convert to 24 hour format so that the object 'testtime24hour' is: '13:00:01' Thanks. -- r2151