Thomasines fast on Wednesdays and Fridays in accordance with the Biblical command found in the Didache (8:1): “Fast on the fourth day and the eve of Sabbath.”
The “eve of Sabbath” begins on Friday night at sundown.
Our fasting begins at sunrise and ends after sunset, on both Wednesday and Friday. These fasts are “liquid fasts”, so solid foods are not to be consumed, but drinks, beverages and broths are acceptable. With the exception of infants, elderly or those who are ill, Thomasines additionally refrain from dairy products on Wednesdays. Similarly, on Fridays, we refrain from food products that contain meat.