Unlike the last ten days of Ramadan where Laylatul Qader is hidden, the ten days of Thul Hijja are appointed and well-known.
Another chance of forgiveness & nearness!
"و يذكروا اسم الله في أيام معلومات" الحج ٢٨
“and to mention the name of Allah on well-known, appointed, days” Alhajj 28
