Tibetan festivals are held according to the Tibetan lunar calendar, which usually lags at least a month behind our Gregorian calendar. The following are some of the more important festivals. You might try to plan your trip to coincide with these festivals. You will need to ask around for the exact dates of many festivals because these are often only fixed by monasteries a few months in advance.

January
Shigatse New Year Festival - Held in the first week of the 12^th lunar month.

February - March
Year End Festival - Dancing monks can be seen on the 29th of the 12th lunar month in this festival which is held to dispel the evil of the old year and to auspiciously usher in the new one.
New Year Festival (Losar) - Taking place in the first week of the first lunar month, Losar is a colorful week of activities; Lhasa is probably the best place to be. There are performances of Tibetan drama and pilgrims making incense offerings. The streets are thronged with Tibetans dressed in their finest.
Lantern Festival - This is held on the 15 ^th of the first lunar month; huge yak-butter sculptures are placed around Lhasa's Barkhor circuit.
Mönlam (Great Prayer Festival) – Held midway through the first lunar month (officially culminating on the 25 ^th). Monks from Lhasa's three main monasteries assemble in the Jokhang and an image of Jampa (Maitreya) from Lhasa's Jokhang is borne around the Barkhor circuit, attracting enthusiastic crowds of locals and pilgrims. The festival was first instituted by Tsongkhapa in 1409 at Ganden Monastery.

May - June
Birth of Sakyamuni (Sakya Thukpa) - This is not exactly a festival, but rather the seventh day of the fourth lunar month is an important pilgrimage date and sees large numbers of pilgrims in the Holy City of Lhasa and other sacred areas in Tibet. Festivals are held at this time at Tsurphu, Ganden, Reting and Samye Monasteries.
Tsuphu Festival - Cham dancing (ritual dancing carried out by monks) and chang drinking are the order of the day at this festival on the 10^th day of the fourth lunar month. The highlight of the festival is the dance of the Karmapa (the spiritual leader of the Karma Kagyupa suborder, now in India).
Saga Dawa (Sakyamuni's Enlightenment) - The 15 ^th day of the fourth lunar month (full moon) marks the date of Sakyamuni's (Sakya Thukpa's) conception, moment of enlightenment and entry into nirvana. It is an occasion for outdoor operas and also sees large numbers of pilgrims at Lhasa's Jokhang and on the Barkhor circuit. Many pilgrims climb Gephel Ri, the peak behind Drepung Monastery, to burn juniper incense. Saga Dawa is also a particularly good time to be at Mt. Kailash.

June - July
World Incense Day - A day of incense burning and picnicking.
Gyantse Horse-Racing Festival - A traditional festival whose date authorities are trying to fix to the middle of June to boost the number of tourists. The fun and games include dances, picnics, archery and equestrian events.
Worship of the Buddha - During the second week of the fifth lunar month, the parks of Lhasa, in particular the Norbulinka, are crowded with picnickers.
Tashilhunpo Festival - During the second week of the fifth lunar month, Shigatse's Tashilhunpo Monastery becomes the scene of a three-day festival, and a huge thangka is hung.
Samye Festival - Held from the 15^th day of the fifth lunar month (full moon) for two days. Special ceremonies and cham dancing in front of the Ütse are the main attractions.

August - September
Chökor Duchen Festival - Held in Lhasa on the fourth day of the sixth lunar month, this festival celebrates Buddha's first sermon at Sarnath near Varanasi in India.
Guru Rinpoche's Birthday - Held on the 10 ^th day of the sixth lunar month, this festival is particularly popular in Nyingmapa monasteries.
Ganden Festival - On the 15^th day of the 6^th lunar month, the Ganden Monastery displays its 25 holiest relics, which are normally locked away. A large offering ceremony accompanies the unveiling.
Drepung Festival - The 30 ^th day of the sixth lunar month is celebrated with the hanging of a huge thangka at Drepung Monastery. Lamas and monks perform masked dances.
Shötun (Yogurt Festival) - Held in the first week of the seventh lunar month, this festival starts at Drepung and moves down to the Norbulinka. Operas and masked dances are held, and locals take the occasion as another excuse for more picnics.

September - October
Bathing Festival - The end of the seventh and beginning of the eighth lunar months sees locals washing away the grime of the previous year in act of purification that coincides with the week-long appearance of the planet Venus in the night sky.
Horse-Racing Festival - Held in the first week of the eighth lunar month, this festival featuring horse racing, archery and other traditional nomad sports is held in Damxung and Nam-tso. A similar and even larger event is held in Nagchu a few weeks earlier.
Onkor - In the first week of the eighth lunar month, Tibetans in central Tibet get together and party in celebration of this traditional harvest festival.

November - December
Lhabab Düchen - Commemorating Buddha's descent from heaven, 22^nd day of the ninth lunar month sees large numbers of pilgrims in Lhasa.
Palden Lhamo (Shri Devi) - Held on the 15^th day of the tenth lunar month, this festival features a procession in Lhasa around the Barkhor bearing Palden Lhamo (Shri Devi), protective deity of the Jokhang.
Tsongkhapa Festival - Respect is shown to Tsongkhapa, the founder of Gelugpa order, on the anniversary of his death on the 25^th of the tenth lunar month. Monasteries light fires and carry images of Tsongkhapa in procession. Check for cham dances at the monasteries at Ganden, Sera and Drepung.