I would love some opinions on this please. And if you could vote on the poll, that would be great! 
So, a worker does 4-on-4-off shift work. (10 hour shifts .) He gets 20 vacation days a year which is 5 weeks for him. When he books 4 days off, he gets a 12 day break. (The 4 days he booked off - and the 4 days before and 4 days after that he wasn't working anyway. The 'default' days off/his weekend.)
So if he books off 7th, 8th, 9th, and 10th of July - he will have had the previous 4 days off by default (the 3rd, 4th, 5th, and 6th,) and he will also get the next 4 days off by default (after the 4 booked days) the 11th, 12th, 13th, and 14th. Due back in on 15th July. 12 days off.
So he finishes work on the 2nd, and is due back in on the 15th. As he has booked time off, he and his family book a 5 day holiday (and a meal out, along with a daytrip or two, and a visit to see family 100 miles away.)
Now the question. Is it, or is it NOT acceptable for his manager to contact him on the 'default' days off? He's off 12 days. He's booked 4 days off, but 8 of the days are not 'booked days.' They are days off though, it's like his weekend.
Is it OK (or not) for the manager to contact him on his 'default' days off/his version of a weekend, asking about work-related issues? Phoning him, and emailing him, and texting him? Asking for responses? And also expecting sometimes for him to pop into the workplace on the days he is not away on holiday? OR should the employee be left alone/left in peace for the 12 days?
I will voice my views later. Just want to put the feelers out and see what people think?
Thanks in advance for your responses.
There are only 32 characters available to put in the options on the poll, so hopefully they make sense. Just 2 responses really. No or yes. Is it OK for the employer/manager to contact an employee on their days off that are not booked days, but are their days off... (Especially when they have plans/are going away for a few days.) Or should they NOT as it is the employee's time off?