Bruno Cocciaro wrote: > sorry for my english but ... what is a leap second ?
The average length of a day isn't exactly 86400 seconds. It varies, somewhat randomly, but recently has been a little longer than 86400 seconds. When the discrepancy between 00:00:00 UTC and solar midnight (nominally at Greenwich, and the definition of midnight is probably more complex than this) significantly exceeds half a second, at the next convenient appropriate time (commonly the end of June or December), 23:59:58.9999999999999999... is immediately followed by 00:00:00, or 23:59:59.99999.... is immediately followed by 23:59:60, and continues up to 23:59:60.9999..... before going to 00:00:00, depending on the direction of the correction. These are leap seconds. NTP time is based on UTC time, so will have an upset, especially for inserted leap seconds, across the leap second. GPS time does not have leap seconds, but GPS does transmit leap second information, so that GPS receivers can present UTC time to users. _______________________________________________ questions mailing list questions@lists.ntp.org https://lists.ntp.org/mailman/listinfo/questions
