How do I calculate time?

how do I calculate time,I mean if I want to make that if the player don't open the game for 24 hours,it will send you a notification to open the game.i already have the notification plugin,I want to know how to calculate time

Take a look at this tutorial:

https://www.scirra.com/tutorials/940/ho ... -a-project

The information in the tutorial will give the browsers date/time value. You could also use the Javascript command Date.now(), which will give you the browsers current time stamp in milliseconds. This value can be easily tested to see if more than a day has passed by getting the difference between the stored time stamp and the current time stamp and converting the result to hours (int(result / (1000 * 60 * 60)))

Thx so much frag father,you solved my problem