My return flight date to UK was originally scheduled for 29 January, I received an email from Air France to say it had been changed to 30th January.
This puts me on one day overstay, I normally go home a couple of days prior to my 90 visa expiry date.
On this trip I have a 60 day visa fortunately I have just received a 30 day extension to the end of February.
I will be reverting back to my 90 day visa for future trips, and returning a couple of days prior to. visa expiry again.
TLDR : Answer Summary
The user experienced a one-day overstay in Thailand due to a change in their flight schedule. They mentioned that they have a 60-day visa and subsequently received a 30-day extension. Community comments clarified that a one-day overstay typically doesn't incur a fine and that Thai immigration is generally understanding of such situations, especially when they are out of the traveler's control.