rolfarius
I have changed the BIOS time … and the time zone to Colombo instead of Bangkok (I think that’s what I’ve set in Lubuntu long ago). Now it is correct.
The problem was most likely the bios time was set in between two time zones, what I never realized on the other OS, Lubuntu as it it always adjusting the time via internet whatever time is set in the bios (sometimes I remember vague, the time was wrong on that OS too, probably when there was no internet).
Now the problem is solved (don’t know how to mark here as solved). Thanks all the posts 🙂
And thanks @afghan for all the notions – I have no Windos on that harddrive (exept an XP as a virtuel machine). Only an offline windows is good windows 🙂
The aspect of RTC -UTC I have to check maybe that was behind it…
Keeping the same time configuration across the systems you use is essential to consistently setting up and maintaining an accurate time
thats indeed the cruicial point 🙂