The 2015 school holidays calendar has been officially released by the MOE. You can check all the dates by scrolling down, remembering to look at your correct table (whether Kumpulan A or Kumpulan B).
The dates below are from the MOE website, so are considered the official school holidays dates for 2015.
Kumpulan A Schools 2015 (Johor, Kedah, Kelantan, Terengganu)
[Kumpulan A 2015] Start date End date
Term 1 holidays 13 March 21 March
Mid-year holidays 29 May 13 June
Term 2 holidays 18 September 26 September
End-year holidays 20 November 2 January (2016)
Kumpulan B Schools 2015 (Kuala Lumpur, Labuan, Melaka, Negeri Sembilan, Pahang, Perlis, Penang, Perak, Putrajaya, Sabah, Sarawak, Selangor)
[Kumpulan B 2015] Start date End date
Term 1 holidays 14 March 22 March
Mid-year holidays 30 May 14 June
Term 2 holidays 19 September 27 September
End-year holidays 21 November 3 January (2016)