Why cant I edit events that are in the past?

Hi,
in general you don't need to edit events in the past.

To remove this limitation edit BeforeShowList events for monthly and weekly views, List page: After record processed event for daily view.

For example find this code:

if ($_SESSION["UserID"]=="Guest" || ((strtotime(now())-strtotime($datatmp2["DateField"]." ".$datatmp2["TimeField"]))>=0 && $datatmp2["DayEvent"]!=1 || (strtotime(date("Y-m-d"))-strtotime($datatmp2["DateField"]))>0 && $datatmp2["DayEvent"]==1))

and replace it with this one:

if ($_SESSION["UserID"]=="Guest")

Hi,

I have made these changes and still can't edit events from the past. Making this change didn't change anything in the monthly or daily views. The weekly view looks like it is editable but when you try to save the changes I get a Java script error "Error Date or Time" from the server.

It's difficult to tell you what's happening without seeing actual files.
Please publish your project on Demo Account and open a ticket at http://support.xlinesoft.com sending a URL to your pages along with instructions on reproducing this error.
Regarding the Error Date or Time error.

Date and time are checked in the BeforeEdit event for daily view.