Leap Second Time Adjustment Day

Annual event.

Dates:
2005Dec 31Sat
2008Dec 31Wed
2012Jun 30Sat
2015Jun 30Tue
2016Dec 31Sat
Inception Year:
1972
Hashtags:
References:
nationaldaycalendar.com/leap-second-time-adjustment-day-december-31/
timeanddate.com/time/leapseconds.html
en.wikipedia.org/wiki/Leap_second