Every year, usually between mid July until mid August, Indonesian government releases the official list of dates of national holiday. For year 2013, I got the information from http://www.kemendagri.go.id/news/2012/07/20/pemerintah-rilis-jadwal-libur-nasional-2013. Here is the calendar.
There are dates marked in yellow, it would be days of “cuti bersama” (collective annual leave). Government companies and most of private companies would be close, but public service in hospital should be operating as usual. People (locals and visitors/expatriates) usually use these extra off-days for vacation.
So, let’s make travel plan. ;)