Without plugins: https://www.scirra.com/tutorials/940/ho ... -a-project
Advanced: Convert each part of the date/time to an integer (total time in seconds). You can then store or compare this value upon startup or save.
Dependent on system time, so can be cheated by adjusting date/time on system.
There may be a way to get the current date/time from a time server, but I am not familiar with the method.