Between the period he embraces Islaam and [openly] announces his [embracing of] Islaam, is the new Muslim required to perform the obligatory acts as required of [all] Muslims?
All Praise be to Allaah alone, and may the prayers and salutations be upon His Messenger and his companions; To proceed:
When a person embraces Islaam, then [as a Muslim] – according to his ability – he is [now] required to gradually learn that which is required of him – as legislated. He is [then] required to act accordingly, and that is from the date he embraced Islaam.
And with Allaah lies all success and may Allaah send prayers and salutations upon our Prophet (sal-Allaahu ‘alayhe wa sallam) and his family and his companions.
The Permanent Committee for Islaamic Research & Verdicts
Fataawa al-Lajnah ad-Daa.imah lil-Buhooth al-‘Ilmiyyah wal-Iftaa – Fatwa No.6348
Fataawa ad-Da’wah wal-Jamaa’aat al-Islaamiyyah – Page 85