All of them brought a new calendar? Or, did their followers start counting days and years from a significant event in their prophets life? And, what if there was no new calendar, then they weren't a true messenger?
Hindu calendar is not related to life of any person that we worship. It was based on an astronomical event, the vernal equinox, in the original home of Indo-Eurorans. When the they left their original homeland, the pattern of weather in the new lands changed. That was because of the precession of equinox over many millenniums. We changed the beginning of the year by three months over a period of some 6,000 years. Finally we shifted to a calendar based on zodiac, entry of sun in the zodiac of the Ram (Mesha). Calendar and its synchronization with weather is an astronomical event. It has to be changed by one month every 2000 years. If the calendar is not changed you will find Christmas shifting to autumn in 6,000 years. If any calendar does not take it into consideration, it will go wrong in time.
We do have festivals related to Gods and Goddesses we worship and persons we rever, e.g., Holi, Diwali, Guru poornima (Full Moon in June \ July), related to the compiler of Vedas and the writer of Mahabharata and many other books, Sage VedaVyasa; and Valmiki Jayanti (Full Moon in October \ November), related to the writer of Ramayana, Sage Valmiki.
Christmas, which has been borrowed from the Romans (Festival of the Sol Invictus), is really the uncorrected beginning of the year of Indo-Europeans. Roman calendar-keeping was very poor and it was politically inspired.