According to Fatawa of most Marajay
1. Ayatollah Khoi
2. Ayatollah Syed Ali Khamnai
3. Ayatollah Sheikh Bashir Najfi
4. Ayatollah Waheed Khorasani
Tomorrow (Saturday the 27th of May) is the 1st of Ramadan.
For Muqalideen of Ayatollah Ali Sistani the 1st of Ramadan is Sunday the 28th of May.