Uposatha Calendars 2018

These are the calendars for the Theravāda uposathas being held in 2018. They mostly agree again this year, except for the Dhammayut Nikāya uposathas, which invariably differ from the others.

One place they do disagree, however, is on the timing of Vesak. There are 10 uposathas in Gimhāna this year, which means an extra month has to be inserted into the season.

Thailand, Cambodia, Laos, Malaysia, Singapore and Indonesia all insert it before Vesak, making that Full Moon fall in May; on the other hand, Myanmar, Sri Lanka, Bangladesh and India insert the extra month later, which makes their Vesak fall in April.

I have also included a calendar of the astronomical Full and New Moons, which differ from the Theravada uposatha timings, which are worked out mechanically.

For those wanting more information on how the calendars are calculated please see this post: Days, Months and Seasons in Pali.

For various reasons – such as there being easily available apps for mobile, etc. – I decided to discontinue making these calendars after 2018.