I have measurements creating 15-min average values for irradiation, air temperature, etc. My measurements start end of October 2014 and run into the new year. The time stamp from my datalogger lists the end time of the intervall. When importing the data into PVsyst v6.38 I get an error when entering the new year. It states I only have 2 values for the year. It seems to me that the system, when subtracting 15 minutes from my time stamp, doesn't step back to the previous year. I.e. the ASCII data line with time stamp 2015-01-01 00:00 (YYYY-MM-DD HH:MM) is assumed to be data for the 15 minutes intervall starting at 2015-12-31 23:45 (this I can see in the error message). While it should be the same day of the year, same time, but year 2014! After checking validity of my data, changing decimal separators, etc. and wasting quite some time, I tried to change the time stamp in my ASCII file to the start time and changing import parameters accordingly. Then the data imported fine. You can try with any data, but I attached my CSV file and import settings (you have to change them to end time to reproduce the problem) By the way, why can't I run a simulation for a part of the year? I only have measurements for about 8 months (yet) that I want to use in simulations, but PVsyst only lets me use a site with full annual data. Regards, Michiel van Noord Consultant Solar Energy Sweden
