Answered by Shaykh Faraz Rabbani
Walaikum assalam wa rahmatullah,
- It is obligatory to seek to be within 45 degrees either way of the Qibla, and blameworthy (but neither sinful nor invalidating) to face away from the exact direction when known. [Binnori, Bulghat al-Areeb]
- When you don’t know the direction of the qibla, take the means to determine the general direction. Ask a local, when possible. Otherwise, make a reasoned estimation. After this, if you erred, your prayer will be valid.
- If after having made a reasoned judgement, you continue. If without this, you have to start over. [Ibn Abidin, Radd al-Muhtar]
- For makeup fasts, the intention must be made before Fajr time enters. For details, see: The Essentials of Fasting at www.sunnipath.com.
And Allah alone gives success.