When you click the "Sync Now" button you are presented with four different types of syncing, each with a unique purpose.
Full Sync: A full sync will first go to your SIS and pull a fresh data load, compare the data and filters to what we currently have stored in SchoolCal for your users and send any changes, additions or deletions to their calendar. This sync is useful if you have made changes in your SIS that quickly need to be reflected in your users calendar. It is the same process that runs in the overnight when you have automatic syncing turned on.
Lite Sync: Lite sync will work with the data that is already loaded into SchoolCal from your SIS (typically has been reloaded during the nightly sync) and will compare the data and filters to what we currently have stored in SchoolCal for your users and send any changes, additions or deletions to their calendar. This is useful if you have made either filter changes or template changes and you want to push them to your users' calendars.
Catalog Sync: When SchoolCal writes an event to your user's calendar we store a local copy. Since people are able to alter their calendars, once a week we automatically "Catalog" the user's SchoolCal events to make sure that we have the most accurate list of events for the users. This takes part on the weekends and is included in either your Saturday or Sunday nightly sync. If you need this cataloging to happen sooner (typically this would be when a user has let you know that they accidentally deleted a class from their calendar), then you may use this "Catalog Sync". It is a longer job than the Full Sync as it is doing an extra step, first getting fresh data from the SIS, then getting fresh data from the user's calendars and finally sending any updates back to their calendar.
Test Sync: A Test Sync uses the data stored in SchoolCal, compares it against your filters, and shows the events that would be created if you ran one of the other sync types or allowed the overnight process to run. It is especially useful when you are making filter or template changes and want to preview the impact. On the job page, the results may show something like 0/1234 events deleted, indicating how many events would be updated, deleted, or added if you were to run the job.