How can I edit the timetable saved online

All your timetables you can find in Timetables administration. Please see: How can I get to Timetables online administration

There you can easily edit your last saved timetable (even from PC version of aSc Timetables software), or any other file.

Select the timetable file and click "Open" button. Program opens the last official version of your timetable on the new tab. You can work on your file in the internet browser directly and no installation is necessary.

Note:
In case, that the official version is not the latest, the new dialog with versions will be opened and you can choose, which version you wish to open. Please, see this:
How to open previously saved versions of my timetable online