How long was the work day? Did enslaved workers have holidays?

Length of work days and holidays varied for enslaved people at Monticello. There are no direct references to the work day for enslaved farm laborers at Monticello. As was true throughout the south, they probably worked from dawn to dusk, with shorter or longer days according to the season. The work day of enslaved house servants was unpredictable, as they were "on call." Certain tradesmen doing work that could be measured were "tasked." Each day a nailer might have to make ten pounds of tenpenny nails.  A cooper had to finish four flour barrels. Wagoners had to transport a certain number of logs. Weavers had to produce seven and a half yards of linen shirting in summer. There is evidence that Jefferson designed tasks to fill the daylight hours. In his chart of work for the spinners and weavers, their task grows with the light from January to June so that their winter work day was nine hours long, while in high summer it lasted fourteen hours.

Enslaved workers at Monticello could pursue their own activities in the evenings, on Sundays, and on some holidays. The usual holidays on slave plantations in Virginia were Christmas, Easter, and Whitsun. There are numerous references to the Christmas holiday (usually several days long) in Jefferson's records.

Was child labor used at Monticello?

Yes, enslaved children were forced to labor on this plantation. Boys and girls under ten assisted in the care of the very young enslaved children or worked in and around the main house. From the age of ten, they were assigned to tasks—in the fields, in the Nailery and Textile Workshop, or in the house. In 1796, for instance, eight of the fourteen nailmakers were aged ten to twelve. At the age of sixteen, enslaved boys and girls were considered full-fledged workers,  tasked as farm laborers or forced into trades.

Did Jefferson pay any of his enslaved laborers?

Some enslaved people received small amounts of money, but that was the exception not the rule. The vast majority of labor was unpaid.

The only enslaved person at Monticello who received something approximating a wage was George Granger, Sr., who was paid $65 a year (about half the wage of a white overseer) when he served as Monticello overseer. Jefferson paid enslaved persons for work outside their normal work day ("in their own time") and for performing unusually difficult or unpleasant tasks like cleaning the chimneys or the privies. Enslaved people working in important positions—such as butler Burwell Colbert and woodworker John Hemmings—received annual "gratuities" of $15 or $20. Jefferson gave men in management positions—George Granger, Jr., in the nailery and Joseph Fossett in the blacksmith shop—a percentage of the profits of their operations.

While in France, New York, and Philadelphia, Jefferson paid James Hemings a wage for being a chef ,valet, and butler for his household. Although Hemings was enslaved by Jefferson at the time, slavery was illegal in France and Jefferson was required to pay Hemings.    

The amount of money was drastically less than what a white worker would have received for the same labor, but Jefferson paid some skilled workmen (coopers and charcoalburners) special premiums for productivity and efficiency. Young workers, like the boys in the Nailery, were encouraged to be more industrious by non-financial incentives, such as special clothing and meat rations.

Some enslaved people at Monticello, primarily members of the Hemings family, were given permission to hire themselves out and keep their wages.