The project contract of employment is very smililar to a fixed term or temporary contract of employment.
In this case, instead of listing a starting date and an ending date, the project contract of employment is a contract where an employee is employed to complete a certain project.
In other words, the date of completion of the project is unknown - it may be six months, it may be 12 months or even longer. The employee is thus bound by the project, and not by dates.
The contract will have wording something like:
“The employment shall commence on (stipulate starting date) and shall end upon completion of the project.”