Correction:
Summary of December 17 (Official start of ER: Dec17, 17:00 JST (8:00 UTC))

Duty cycle computed from Observation mode duration

From 17:00 JST (8:00 UTC) to Dec.18 9:00 JST (Dec18 00:00 UTC) (Total time: 57600 sec)
Total Observation mode duration: 56056 sec, 15.57 hours
Duty cycle 97.3%

Observation mode start Observation mode end Duration[sec] BNS range
December 17 2019 08:00:02.000 December 17 2019 12:52:51.000 17569 8kc
December 17 2019 13:02:25.000 December 17 2019 20:32:23.000 26998 6-7kc
December 17 2019 20:39:42.000 December 17 2019 23:51:11.000 11489 6kpc
(Time is UTC)