The Windows schedule or Windows Timeline is one of the most anticipated features in Windows 10 April 2018 Update. Microsoft has announced this feature for quite some time, but made it official this year.
The Windows Timeline feature should (logically) work normally after the installation of the new system, but unfortunately it does not happen to everyone. 
It seems that although the Timeline appears in the UI it does not save your activity. Here are some details that you should check if your Timeline does not work.
Mention that the Timeline takes at least one day to gather your activity. So to see some activity you have to spend at least 24 hours from it information.
Check if Timeline is enabled
Make sure the new feature is enabled, ie you should allow it collection του ιστορικού των δραστηριοτήτων σας. Ανοίξτε την εφαρμογή Ρυθμίσεις και στις Privacy Settings select her tab Activity history.
Make sure “I allow Windows to collect my activities from this person” is selected computer".
Clear activity history
You may need to clear your business history. Open the Settings app, and from the Privacy tab, select the Activity History tab again. 
In the Clear Activity History section, click the Clear button. You can do it even if the Windows 10 they didn't have time to collect your activities.
Temporarily switch to a local account
This solution may be a little annoying but it seems to work. Open the "Settings" application and from "Account Settings" go to "Information". Click "Sign in to a local account" (not a Microsoft account) and you will see that the Timeline will work just fine on your local account.
You may need to stay in the local account for a while before switching to a Microsoft account. Many users they state that switching to the local account will fix Timelines not working, however you will need to use your computer for a while with a local account.
To mention that all the above kombogiannitika solutions it wouldn't be needed if Microsoft did their job right. The above solutions are from reddit and forums where too many Windows users are trying to fix their system after last update.
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