The Prophet (saw) used to fast on Mondays and Thursdays
?The most beloved prayer to Allaah is the prayer of Dawood (peace be upon him), and the most beloved fasting to Allaah is the fasting of Dawood. He used to sleep half the night, stand in prayer for one-third of the night, and sleep for one-sixth, and he used to fast alternate days.? (al-Bukhaari, 1131; Muslim, 1159).
The Prophet (peace and blessings of Allaah be upon him) was asked about fasting on Mondays and Thursdays, and he said: ?Those are two days on which people?s deeds are shown to the Lord of the Worlds, and I want my deeds to be shown to Him when I am fasting.? (al-Nasaa?i, 2358; Ibn Maajah, 1740; Ahmad, 8161; classed as saheeh by al-Albaani in Saheeh al-Jaami?, 1583). He was asked about fasting on Mondays and he said, ?On that day I was born and on that day revelation came to me.? (Muslim, 1162).
The Prophet (saw) passed away on his birthday, so keep in mind any celebration would also be conducted the day of his passing.
From a personal perspective, it looks to me like the Prophet (saw) used to fast on his birthday and the day he first received revelation as an act of gratefulness to Allah, Allah said, 'All the deeds of Adam's sons (people) are for them, except fasting which is for Me, and I will give the reward for it.'
I try to fast Mondays and thursdays, to make up the fasts I miss during Ramadan mostly, but also to follow sunnah (it's much easier in winter than summer tho!).
Also anyone else read of the current research being done on the health benefits of the alternate day diet? diet