We are coming to the end of the year according to the calendar of the Prophet ﷺ. These are the days we celebrate and that are made holy for us. They cannot be changed for other days or other calendars. This is the calendar Sayyidunā l-Mahdī (as) is following. The Hijrī New Year is a time to ask forgiveness for the mistakes of the last year and blessings for the coming year.