On the holy week is the week which we observe and respect because is the final week of Jesus Christ on earth, which comprises of his suffering, crucifixion, death and resurrection. The things which happened during that time are recorded in the bible. So all the events that took place during the holy week are all recorded and found in the bible.
The bible did not mention that we should observe holy week, but holy week was invented by christians. Observing Holy Week is therefore a Christian tradition rather than a direct biblical command. It can be beneficial when it helps believers reflect on Christ’s sacrifice, but it should not be presented as a requirement for salvation or as a law that every Christian must follow.
In other sense, all the events that happened during holy week are recorded and official in the bible. Christians may choose to observe it as a meaningful time of prayer, reflection, repentance, and worship. The most important thing is not the tradition or the particular days observed, but keeping Jesus Christ, His death, and His resurrection at the center of Christian faith and worship.