It will be restocked at 12:00 PM at on the first day of every month regardless of how many days there are to that month.
If I am correct the GMT is -7 and the current time according to the Toribash web page can be found at the bottom of this http://forum.toribash.com/ From there you can calculate the time change and then there you go.
I have heard no for sure time. The first is all I was able to find out. SlipAnc said that he assumed it would restock when the forums backup at 10 GMT 0
A certain recluse, I know not who, once said that no bonds attached him to this life, and the only thing he would regret leaving was the sky.