The only format allowed in date and date/time keys in source mode is the ISO8601 one … which is then parsed in the format set at your device OS level by Properties in Live Preview and Reading …
So, date and date/time keys needs to be written as YYYY-MM-DD or YYYY-MM-DD[T]HH:mm to be parsed correctly by Properties, otherwise it can lead to some unexpected results, like what you’ve encountered here (the day part was parsed as the year and the first 2 digits of 2024 were taken as the day).
Edit: Here’s a post with a longer explanation about what’s happening with the “wrong date”: here