"At this point, we're expecting the wedding to be at the end of the summer, just before Labour Day Weekend (September 2)."
The former Friends star - who got engaged last summer - admitted recently that she hasn't had time to select her wedding dress because she is so busy.
Aniston was previously said to have found her first wedding to Brad Pitt in 2000 "stressful".
Her wedding planner Kevin Lee claimed she was uncomfortable with the lavish celebration - which cost a rumoured $1 million and included a 13 minute-long fireworks display and 50,000 flowers -and is planning a very different ceremony with Justin.
He said: "They won't be blowing millions on an over-the-top wedding with hundreds of people they barely know. Brad wanted that when she married him, and she got caught up in having a huge day.
"It was ultimately so stressful that she couldn't really take time to enjoy it. So it's going to be small and low-key so they feel relaxed."
- Bang! Showbiz