qtrthr, I hold a Singaporean Driving Licence and I tried to convert it to Qatari one, but it was not possible. As a matter of fact, I'm going for the driving test tomorrow morning at 5.30am.

Prior to this, the Qatari traffic department require that your Singapore Licence attestated as well as without an expiry date. You have to go to the Singapore Embassy, with the Driving Licence, and NRIC or passport, and the Embassy will give you a letter of attestation. With that, then you can apply for a test date directly.