Two hours missing from stats on 13th March 2016, daylight savings day

I have just noticed that 2h and 23h stats are missing on “Visits by Server Time” graph in Piwik 2.16.0 for date 2016-03-13. This was daylight savings day for USA. If one hour of stats was missing I would attribute that to DST, but why would two hours of stats be gone?
Both server and PHP have timezone set to UTC, while tracked sites have America/Detroit set as timezone. I have already invalidated reports for 2016-03-13 and recreated them, but that did not help.

Is there anything I can do to have stats for all 24 hours on 13th March 2016?

Could you create an issue on Github. Please attach as many information as possible, e.g. screenshots, etc.