Year to date (YTD) is a time period that starts at the beginning of the current year and goes up until the present date. It's often used to track financial performance, such as income, expenses, or gains/losses over a specific period. YTD calculations are useful in comparing current performance against past performance, as well as in projecting future performance.

In terms of payroll, YTD refers to the total amount of pay an employee has received from the start of the year to the current date. This information is typically found on an employee's pay stub and is used to calculate the employee's tax liability and other deductions, such as 401(k) contributions.

Overall, YTD provides a snapshot of progress or performance over a specific period and is used in a variety of industries and areas, including finance, accounting, and human resources.