.WEA files from TMY and IWEC

Hello All,

Could someone please help with an explanation for the following - when
using Daysim with weather files created from TMY data (such as US
locations), the .wea file has timestamps equal to integer hours. However,
for some other locations (I have seen them with files created from IWEC
data), the timestamps are half-integers (8.5, 9.5 etc). I am not sure what
is causing this difference. I'm using Daysim 3.1 on windows.

I am doing nothing different except changing the weather file. Any help
would be appreciated.