[time-nuts] When does NIST change to DST?

Scott Newell newell+timenuts at n5tnl.com
Tue Mar 15 20:02:19 EDT 2016


I've been recording the WWVB timecode output from a salvaged walmart 
clock module, so I examined the recent changes at bits 57 and 58. 
Looks like they got it exactly right. Here's the minute before and after.

Midnight Saturday (UTC), they turned on bit 57 to indicate DST begins Sunday:

Sat Mar 12 23:59:57 2016 |  ----------
Sat Mar 12 23:59:58 2016 |   ----------

Sun Mar 13 00:00:57 2016 |  -------------------------
Sun Mar 13 00:00:58 2016 |  ----------


And midnight Sunday, they turned on bit 58 to indicate DST is in effect:

Sun Mar 13 23:59:57 2016 |  -------------------------
Sun Mar 13 23:59:58 2016 |  ----------

Mon Mar 14 00:00:57 2016 |  -------------------------
Mon Mar 14 00:00:58 2016 | --------------------------


(If there's any interest, I can go back to last fall and see if they 
got the standard time transition correct.)


-- 
newell  N5TNL



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