Chaitra, Caitra

In Indian astronomy, Caitra or Chaitra (चैत्र) is the Sanskrit name of a lunar month in which the full moon stands in the constellation Chitrā (corresponding to March-April).
In the Vedic calendar, it is the first month of the vasanta (season of spring), presided over by Vishnu.
In Pancaratra tradition, Chaitra is the first month (caitra-masa: April-May), during which are celebrated the birthday of Rāma and of Narasiṃha, as well as the flower festivals called vasantotsava, damanotsava and kalhārotsava [alternatively in the following month of vaiśākha: ay/June].
In Southeast Asia, it is a 29-day month, the first month of the year. Khmer linguists define chetr as the fifth month of the lunar calendar.
In Madurai (India), Chaitra month is when the marriage of Shiva and Mīnākshī is celebrated every year. during the month of Chaitra.
Zhou Daguan noted that in 13th centurt Angkor Khmer New Year fell in the tenth month of the Chinese calendar, called "jiade" (for Katejk-Karttika, kh កត្តិក Khatdek), Oct-November.

Source

Diana L. Eck, India: A Sacred Geography, London, Harmony/Rodale/Convergent, 2012, p 412.
Wisdom Library.
Chuon Nath Dictionary.