How to extend expiration date?

how to extend global expiration date
like if user has bought for another 1 year
how to extend expiration date

The expiration date feature shouldn’t be used if you want to extend expiration date. Use Obsidium to sell expiring licenses.

Is it possible that someone can bypass global expiration date by changing system clock or running the app in a virtual environment ?

There is a built-in clock change detection protection in ExeOutput. If the user changes the date back, the key is automatically expired.

Of course, offline expiration date system are always weak compared to systems with a remote server check.