The six month cooling period is statutory and cannot be shortened. Your marital status on Dec. 31 will determine how you will file tax return next year.
If you file a legal separation, the court may likely dismiss the action per pending divorce action. If you really want to do it, you may file a petition to dismiss the divorce action first, then file a legal separation. There is no guarantee you will get both dismissal and legal separation approved by the court before Dec. 31. In addition, you will have to refile the divorce petition next year, pay the fee again, and start the six month period again.
