Is re-praying Maghrib valid, based on doubt concerning its time having expired due to an error in calculating the midpoint between Maghrib and Isha?

The Maghrib prayer is valid if performed after verifying the sunset, and it is not legislated to repeat it without a valid Shar’i reason. There is no harm in repeating it due to forgetfulness or ignorance. The time for Maghrib extends until the disappearance of the red twilight (the entry of the Isha prayer time), and its necessary time for those with excuses extends until dawn.