Same thing I wrote in another post:
I have the same station and the same problem. After some experimention, I think I have the exact nature of the problem (but don't yet have a solution). (This on Windows NT, I haven't tested on XP yet to see if it is better.)
- The base unit reads the data (up to 175 points) and stores them with the time (I don't know if the base unit DST offset is used or not for the recorded points.
- Heavy Weather is used to download the data.
- Heavy Weather reads the data and converts the date to GMT/UT and stores the data in history.dat in UT form.
- Problem 1: HW does not count for daylight saving, it only uses the raw timezone offset. So in my case (NZ) it subtracts 12 hours from the datetimes and stores them.
- When Heavy Weather displays or Saves the data, it re-adds the timezone offset, again ignoring any DST.
- Heavy Weather Review loads history.dat and graphs the data.
- Problem 2: HWR does not add any timezone offset at all, it just displays the UT datetimes.
- Problem 3: HWR adds 1 hour if the Windows timezone has daylight saving adjustment selected, but it adds 1 hour all year round, not just when DST is active in the summer. It just looks at the Windows timezone "Automatically adjust clock for daylight saving changes" checkbox, but does no test to check if DST is actually active.
@John G: Is that the same you are getting?
Given the previous 4 year old mentions of the same problem, I think I am about to try and patch HWR and HW to remove all of the crap DST handling code...