If you have a business trip that requires a Friday and Monday meeting and it is not cost effective to fly home and back to the client, then you can stay over the weekend and the days count as business days, not personal. To qualify for the deduction, you need to have more business days than personal days making up the total length of the trip. If that’s the case, you can deduct the entire cost of your transportation for the flight. A business day would be a travel day and any day on which you’re meeting with the client, plus the weekends if you need to meet again on Monday.
For example, if you fly out on Wednesday for meetings on Thursday, Friday and Monday and then stay an extra day on Tuesday for sightseeing, when you come home on Wednesday you will have been away for 8 days. As your business days are 7 (two for travel, three for meetings plus the weekend separating your meetings) and your personal days are 1, you would be able to deduct your entire flight and 7 days worth of parking, hotel and meals (note the meals are still limited to 50%). Hence mixing a business trip and vacation = Businacation. Isn’t that much more fun then a staycation?