I just started..
The date on the model shows 19/6/1811
when I shut down my computer..then restart and check the model again I lose 2 days on it..model shows 17/6/1811 why? did I lose two day. Is there a way to keep from loosing these days?

The model checkpoints every 144 timestamps or every 3rd model day. So if your timeing is bad you will lose 2 days every time it is shut down. If your timeing is good you will pick up right where you left off.
<br>John Keck -- BOINCing since 2002/12/08 -- <a href="http://www.boinc.dk/index.php?page=user_statistics&amp;project=cpdn&amp;userid=191"><img border="0" height="80" src="http://191.cpdn.sig.boinc.dk?188"></a>

It saves at the end of each third model day, and for convenience each month consists of 30 days and each year 360 days.

If you display the graphics you can, therefore, find the next save point quite easily, and choose your shutdown point accordingly.

As Andrew said, view the graphic to see what day you are at. The model year is 12 months of 30 days for 360 days total. So a good time to suspend/halt the model is right after a day divisible by 3 is done. For example just after 0000 UTC/GMT (I usually wait until 0330 just to be safe) on the 1st or 4th or 7th or 10th or 13th, etc. of any given month.