Chaturmas vrat has to be observed for four months starting from Ashada sukla Ekadashi till Karthika Sukla Ekadashi. But few observe this vrat for two months only considering each Paksh as a month. Different people have different opinion on this. People who observe this will observe four vrats during the four months.
The starting of this vrat for 2012 are as follows:
Start Date: 30th June 2012 Ashada Sukla Ekadashi, Sayana Ekadashi
End Date:24th November 2012 Karthika Sukla Ekadashhi, utthaana Ekadashi.
A day long fasting which is ended after worshipping the Lord.
Sanyasis who take up this vrat will not cross the border of the village/city/town in which they take up this Vrat.