Killing our lawn due to creeping charlie
You are not alone in wanting to remove creeping charlie from your lawn. I did years ago because it was taking over everything, including adjoining garden space. Your question has been answered before so I am copying one of the answers to the same question.
Fall renovation is recommended because plants are storing food for the winter and the chemical will be taken into the roots.
"There are many ways to handle creeping Charlie in your lawn. Roundup is not the only approach to killing the entire lawn and doing a total lawn renovation, but that is the best option when your lawn is more than 50% weeds.
If you have less than 50% weeds, and would like to selectively kill the creeping Charlie, then the Chickweed, Clover and Oxalis Killer containing triclopyr (short name for the chemical you describe) is a good choice. Speed Zone is another effective herbicide for creeping Charlie. You can easily spray either of these products yourself with a sprayer.
Keep in mind that creeping Charlie is a VERY tough weed. Early fall is the prime time to kill it, but it usually takes at least two applications, spaced about 2-3 weeks apart, to really knock it out. That's why you want to start this process early in the fall. Even late August is okay.
If you plan to reseed--and fall is the best time to do that also, the earlier the better--be sure to read the herbicide label carefully to learn how long your must wait to reseed after applying the herbicide.
(About the Round-Up: One good thing about glyphosate is that you can reseed fairly soon after application. About a week. Read the label. Glyphosate is the important chemical in Round-Up and is available in many other products now. It isn't available only in Round-Up anymore.)"