When a new work contract is created, flextime calculation is reset to zero so on the first day of the contract flextime shows 0 hours. If you want to transfer the users flextime, you need to adjust balance manually.

1. Go to Tools - User management
2. Click to Edit an employee
3. On the employee personal settings page, click to expand the Work hour adjustments section
4. Click Add to enter a new adjustment
5. Enter a positive or negative number to change the balance for the same date as the new contracts start date
6. Save