Originally Posted by Allah’sServant
Yes it is Tahajjud. If you didn’t know then it’s fine but it is not permissible to pray a prayer before the time comes in as the prayer time having entered is a condition for the validity of the prayer.
Allah Most High says, “After performing the ritual prayer, continue to remember God– standing, sitting, and lying on your sides– and once you are safe, keep up regular prayer, for prayer is obligatory for the believers at prescribed times.” [4.103]
And indeed Allah knows best.