In the american version of The Office, at the time of their wedding, Jim says that he had to wait for a long long time. Is there any indication to know exactly how much time has passed ?
According to this timeline, Jim started to work in Dunder Mifflin in 2001 (about 4 years prior to season 1). This is supported by Ryan's claim in Dwight's Speech (late season 2) that Jim has been working there for 5 years. And in Launch Party (season 4), he tells Pam he liked her on his first day, when she showed him to his desk. So, since they marry in late 2009, we can assume he waited for about 8 years to marry her.
A lloonnnggggg time. Jim had a girlfriend for a while and Pam went through an engagement before they finally ended up together.
So basically from Season 1 (2005) until their marriage in Season 6 (2010).