There was a report of GPS glitch as large as 13 microsec (http://www.itnews.com.au/news/satellite-failure-caused-global-gps-timing-anomaly-414237) starting around "January 26 12.49 am local time", presumably Mountain Standard Time, so it's probably around Jan 26 07:49 UTC, and was fixed by "6.10 am Mountain Standard Time".

I looked at the timing comparator for the cesium clock (H1:SYS-TIMING_C_MA_A_PORT_2_SLAVE_CFC_TIMEDIFF_1) as well as X end GPS receiver (H1:SYS-TIMING_X_FO_A_PORT_9_SLAVE_CFC_TIMEDIFF_3) and Y end GPS (H1:SYS-TIMING_Y_FO_A_PORT_9_SLAVE_CFC_TIMEDIFF_3).

(It seems like end station GPS units are connected to the second input of timing comparators at each end station at LLO, but here they are to the third input.)

Right plot shows 6-days, and the left one is 4 hours around the reported glitch, and I see no timing jump.