The concept of an annual observance to commemorate a significant event is certainly not unusual. Consider, for example, when a couple celebrate their wedding anniversary or when a nation commemorates an important event in its history.
सहसा एखादा महत्त्वाचा प्रसंग वर्षातून एकदा त्याच्या वाढदिवशी साजरा केला जातो.