Stop and limit orders created outside trading hours are executed at the next possible time during trading hours.
Market orders are generally only valid for the day on which they are created. If they are created before the market opens, they will be executed at the next possible time during trading hours. Market orders placed after the close of trading expire.
A limit or stop order is always valid for one year from the day it is created. After one year, the order is automatically canceled. If necessary, you can of course cancel the order manually at any time. It is currently not possible to adjust this period to your own requirements.
In the case of corporate actions (e.g. dividends and stock splits), orders placed on the security in question are deleted, as corporate actions often lead to sudden price changes. This can lead to unwanted order executions. To protect against these unwanted executions, limit and stop-limit orders are deleted before execution.