Sync works just fine for me. I just synced, and a new item that was just put on the calendar today appeared.
You didn't mention what version of LDS Tools you are using. I'm using LDS Tools 2.2.2.3 for Android.
And what do you mean by "doesn't work"? Do you see any error messages? Do you get the progress gauge, but no calendar entries appear? Do other items (people, leaders) sync correctly?
Questions that can benefit the larger community should be asked in a public forum, not a private message.