When did Betsy Ross take 2 strips off the flag to have 13?

There is no definitive historical record of Betsy Ross removing two stripes from the flag to create the 13 stripes associated with the American flag. The design of the flag, including the 13 stripes representing the original colonies, was established in the Flag Act of 1777. While Betsy Ross is often credited with sewing the first American flag, the specific details of its design and alterations remain largely a matter of folklore rather than documented fact.