Time (UV variable time, in JD) is recorded at the start of an integration interval (UV variable inttime, in sec). For example, for uvgen time=09jul01:10:00:00 harange=0,1,0.1 you will see times:
09JUL01:10:00:00.0 09JUL01:10:05:59.0 09JUL01:10:11:58.0 09JUL01:10:17:57.1 09JUL01:10:23:56.1 09JUL01:10:29:55.1 09JUL01:10:35:54.1 09JUL01:10:41:53.1 09JUL01:10:47:52.1 09JUL01:10:53:51.2
Programs such selfcal and mselfcal extract and average times from these observations and again record the nominal starting time of their interval in the gain tables. uvaver can also average in time.