I quit hunting the last 2 years, moved 500 miles, work 12 hour nights, stayed single for 35 years, and have called in sick (so i could fish) with the following BS stories:
1. Infectious parastitic diarrhea. Story goes that I caught it from eating bad homemade pork jerky. I told the boss I could even see small worms in my stool. Pork jerky, is there even such a thing?
2. Mother has had 2 strokes so that I could chase tuna. It helps to know that she is evil incarnate. Here's how to pull this one off. First have someone call work looking for you, have them tell your manager that they are family and they need to pass on an important message regarding your moms health. Have them mention that your next of kin and they need you to make important medical decisions. Then manager calls you and passes on info, and schedules you off for the week right as the big schools of bluefin tuna show up a 150 miles south of San Diego. I couldn't use this one anymore, but it worked pretty well when I was 23.
WARNING: Don't use this on a job you actually want to keep. Or where they know your family. Or if you have any sense of right and wrong. Otherwise it works great.
3. Horribly weepy, oral herpes outbreak. How to use this one. It good for a couple days off. Use it for when you get any cold sores, and you already have days off after your call-in days. Its great for people in the food service industry. I used it when I was waiting tables.
4. Here's an easy one. "I need the day off because I am having personal psychological issues. I'll be with my therapist most of the day." Then call your therapist, have him/her meet you on the South Fork of the Salmon River with fresh cured roe.
Ok, those are my favorites that have given me a few more days of fishing. Use at your discretion. I make no warranties implied or otherwise, you assume all liabilities.