Observances on non-Gregorian calendars

In the Mandaean calendar, Dehwa Hanina (Classical Mandaic: ࡃࡉࡄࡁࡀ ࡄࡍࡉࡍࡀ, Dihba Hnina) or Dehwa Ṭurma (Dihba ḏ-Ṭirma), the Little Feast, is celebrated on the 18th day of Taura, which is the 4th month of the Mandaean calendar that corresponds to the Hebrew month Iyar.

Hobiyee, also spelled Hoobiyee, Hobiiyee and Hoobiiyee, is the Nisg̱aʼa new year celebrated every February or March. It signifies the emergence of the first crescent moon and begins the month Buxw-laḵs. Celebrations of Hobiyee are done by Nisg̱aʼa wherever they are located, but the largest celebrations are in Nisg̱aʼa itself and in areas with a large Nisg̱aʼa presence like Vancouver.

Nowruz (Persian: نوروز) (lit: "New Day") is the Iranian New Year or Persian New Year. Historically, it has been observed by Persians and other Iranian peoples, but is now celebrated by many ethnicities worldwide. It is a festival based on the Northern Hemisphere spring equinox, which marks the first day of a new year on the Solar Hijri calendar; it usually coincides with a date between 19 March and 22 March on the Gregorian calendar.

In Māori culture, Matariki is the Pleiades star cluster and a celebration of its first rising in late June or early July. The rising marks the beginning of the new year in the Māori lunar calendar.

Quviasukvik (Inuktitut: ᖁᕕᐊᓲᑎᖃᕐᕕᒃ; "Christmas"), is the first day of the year according to Inuit. The festival of the New Year is celebrated by Inuit, Yupik, Aleuts, Chukchi, NunatuKavummiut and the Iñupiat. The feast originally derives from traditional Inuit religion but in modern times, it has Christian influences.

Yhyаkh (Yakut: Ыһыах, Ihıax) is the festival that celebrates the rebirth of nature after a hard winter, the triumph of life, the beginning of a new year in the Sakha Republic. Historic celebration is observed on the 21st June, the day of the summer solstice.

Bon Om Touk (Khmer: បុណ្យអុំទូក, Bŏn Om Tuk, lit. "Boat Paddling Festival"), also known as the Cambodian Water Festival, is celebrated in late October or early November, often corresponding with the lunar Mid-Autumn Festival. It marks the end of the monsoon season. The festivities are accompanied by dragon boat races, similar to those seen in the Lao Boun Suang Huea festival.

Vesak (Pali: Vesākha; Sanskrit: vaiśākha), also known as Buddha Jayanti, Buddha Purnima, Visak Bochea and Buddha Day, is a holiday traditionally observed by Buddhists in South Asia and Southeast Asia, as well as in Tibet and Mongolia. It is among the most important Buddhist festivals. The festival commemorates the birth, enlightenment (Pali: Nibbāna, Sanskrit: Nirvāṇa), and death (Parinirvāna) of Gautama Buddha in Theravada, Tibetan Buddhism, and Navayana.

Thai New Year or Songkran (Thai: เทศกาลสงกรานต์), also known as Songkran Festival, Songkran Splendours, is the Thai New Year's national holiday. Songkran is on 13 April every year, but the holiday period extends from 14 to 15 April. In 2018 the Thai cabinet extended the festival nationwide to seven days, 9–16 April, to enable citizens to travel home for the holiday. In 2019, the holiday was observed 9–16 April as 13 April fell on a Saturday. In 2024, Songkran was extended to almost the entire month, starting on the first of April, and ending on the twenty-first, departing from the traditional 3-day format. And with the New Year of many calendars of Southeast and South Asia, in keeping with the Theravada Buddhist calendar and also coincides with New Year in Hindu calendar such as Vishu, Bihu, Pohela Boishakh, Pana Sankranti, Vaisakhi. The New Year takes place at around the same time as the new year celebrations of many regions of South Asia like China (Dai people of Yunnan Province), India, Laos, Cambodia, Myanmar, Nepal, and Sri Lanka.

Sinhalese New Year, generally known as Aluth Avurudda (Sinhala: අලුත් අවුරුද්ද) in Sri Lanka, is a Sri Lankan holiday that celebrates the traditional New Year of the Sinhalese people and Tamil population of Sri Lanka. It is a major anniversary celebrated by not only the Sinhalese and Tamil people but by most Sri Lankans. The timing of the Sinhala Tamil New Year coincides with the new year celebrations of many traditional calendars of South and Southeast Asia. The festival has close semblance to the Tamil New year and other South and Southeast Asian New Years. It is a public holiday in Sri Lanka (02 Public Holidays - Normally Shops Close for Around One Week Following the New Year). It is generally celebrated on 13 April or 14 April and traditionally begins at the sighting of the new moon.