Policies regarding the amount of vacation time that can be used in conjunction with a foreign business trip differ for the various program offices funding the travel. For trips funded by Environmental Management, the guidelines state 1 day of vacation time for every 2 business days is allowed. The Defense Program specifies 1 day of vacation for every day of business is allowed. Weekends and travel days are not counted as business days. For non-DOE, Office of Science, or domestic trips, vacation time is approved at the discretion of the division.