Dear Stefan and Iain,
I just downloaded several weather datasets (France, population weighted, but I also checked Spain and land area weighted - the issue seems to be in all datasets).
Even though it is specified in the 2nd row of the CSV file:
# Units: time in UTC [...]
I found that there is one missing hour at each last Sunday in March, i.e. when the shift to ‘Daylight Saving Time’ occures [Exception 1980: Here it occures two weeks earlier at the 16.03.1980 ?!] while the 2nd hour occures twices at each last Sunday in October. E.g.:
28.03.2015 23:00 | 25.10.2015 00:00 29.03.2015 00:00 | 25.10.2015 01:00 29.03.2015 02:00 | 25.10.2015 01:00 29.03.2015 03:00 | 25.10.2015 02:00
So, is this just a misunderstanding of wording, thus do you actually mean CET (Central European Time, including DST) instead of UTC (Coordinated Universal Time, which by definition does not do DST-shifting)?
Or, do you maybe have an error in the data processing scripts, i.e. the data is erroneously shifted in the summer period?
Since it might be helpful for inspection, here (sorry, in German! ) is an overview of the dates when DST shifting occure[d/s] (past+future).
Best regards and thank you guys in advance!