Restrict time range of syncronisation
as written here
This would be nice. Syncing my calendar takes quite a bit of time (30-60 seconds), presumably because it's syncing years worth of information every time?
Ideally the initial (and perhaps a manual "full/force resync") sync would sync the complete calendar history, but automatic syncs would only sync events >= one week ago or so.
It doesn't sync the information every time but at least the ETag (hash) for every iCal.
Partial syncs will be a very challenging task, but I will have a look at it when other things are stable.