Is Uposatha on full moons or specific days? I want to start observing Uposatha, but I'm a little unclear on what days it is. I'm finding calendars that it is the days of full moons in Sri Lanka or other countries. Should it just be celebrated on full moons then? For example, I'm in the Midwest of the USA, the full moon in September is September 6 but I'm seeing Uposatha to be August 5 on calendars. Which dates should I observe on? Also, am I correct that the eight precepts to be practiced on Uposatha are: 


Do not take life
Celibacy
Do not speak false, no lies
Do not steal
Do not use any intoxicants
Only eat one meal between dawn and noon (does this need to be vegetarian to fit in with the first precept?)
Do not use a luxurious bed that night, so sleep on a sleeping mat on the ground


Are these correct?
I want to start observing Uposatha, but I'm a little unclear on what days it is. I'm finding calendars that it is the days of full moons in Sri Lanka or other countries. Should it just be celebrated on full moons then?

You can use the calendars from e.g. Sri Lanka, Thailand, Myanmar etc.
More importantly is the practice itself, ie. the deepening of ones practice on special days of the months. Its really that which is essential from a practical Dhamma perspective.
The Wikipedia describes it as;

The Buddha taught that the Uposatha day is for &quot;the cleansing of the defiled mind,&quot; resulting in inner calm and joy. On this day, both lay and ordained members of the sangha intensify their practice, deepen their knowledge and express communal commitment through millennia-old acts of lay-monastic reciprocity. On these days, the lay followers make a conscious effort to keep the Five Precepts or (as the tradition suggests) the Eight Precepts. It is a day for practicing the Buddha's teachings and meditation.

You can use full moon days in your country or you can use the traditional calculated calendar days.

Also, am I correct that the eight precepts to be practiced on Uposatha are. Are these correct?

The Eight Precepts are:


Panatipata veramani sikkhapadam samadiyamiI undertake the precept to refrain from destroying living creatures.

Adinnadana veramani sikkhapadam samadiyamiI undertake the precept to refrain from taking that which is not given.

Abrahmacariya veramani sikkhapadam samadiyamiI undertake the precept to refrain from sexual activity.

Musavada veramani sikkhapadam samadiyamiI undertake the precept to refrain from incorrect speech.

Suramerayamajja pamadatthana veramani sikkhapadam samadiyamiI undertake the precept to refrain from intoxicating drinks and drugs which lead to carelessness.

Vikalabhojana veramani sikkhapadam samadiyamiI undertake the precept to refrain from eating at the forbidden time (i.e., after noon).

Nacca-gita-vadita-visukkadassana mala-gandha-vilepana-dharana-mandana-vibhusanathana veramani sikkhapadam samadiyamiI undertake the precept to refrain from dancing, singing, music, going to see entertainments, wearing garlands, using perfumes, and beautifying the body with cosmetics.

Uccasayana-mahasayana veramani sikkhapadam samadiyamiI undertake the precept to refrain from lying on a high or luxurious sleeping place.




In the comments you asked about the 1st precept;

And should the meal before noon be vegetarian to coincide with the first precept?

Several factors must be fulfilled in order to break the 1st precept.
The five factors of the first precept are:


pano -- presence of a living being.
panasannita -- one knows that it is a living being.
vadhacittam -- the intention to kill.
upakkamo -- the effort to kill.
tena maranam -- the resulting death of that being.


If one of these factors are not fulfilled, the precept is still intact.
For more information, please see &quot;Ask A Monk: Mark Zuckerberg, Vegetarianism and Killing&quot; by Ven. Yuttadhammo.