When rolling over a covered call into a front month Think or Swim has a very handy tool to do this in one transaction instead of the normal two.

Step 1. Find the call option that you sold that is about to expire. Do this at a minimum on the Wednesday before expiration on Friday.Right click on the option and select SELL then roll over this to select Calendar.

Step 2. Two orders will be created instantly. One to buy the current call before it expires (minimum 3 days before expiration) and the other to sell the next month call at the same strike price. You can adjust the limit price to be in the middle of the spread if needed. The beauty is this is just one transaction cost instead of two. Saving money and time. Love it.