I joined this company 2 weeks ago. My employer has offered to include me in the company trip next week, departing on Friday night and returning on Sunday night. If I do not accept the offer, they will deduct 2 days' salary (Saturday & Sunday). We work 1/2 day on Saturday. Do they have the right to do that (deduct salary for Sunday)? They say it's company policy but this was not mentioned in my Appointment Letter.