Description: This is a two-bit code warning of an impending leap second to be inserted in the NTP timescale. The bits are set before 23:59 on the day of insertion and reset after 00:00 on the following day. This causes the number of seconds (rollover interval) in the day of insertion to be increased or decreased by one. The two bits are coded as below, 00, no warning 01, last minute has 61 seconds 10, last minute has 59 seconds 11, alarm condition (clock not synchronized)