Work advice: Can reader have a life and the promotion?

Q: After 18 months at my job at a cafe, I am being promoted to manager. This is really great and I am thrilled. However, one small thing troubles me: I've been told that as a manager, I will need to be "available at all times." When I was originally hired, I said I needed Saturday afternoons off to do bookkeeping for a friend's business, Monday nights for hobby-related group meetings, and Wednesday mornings for charity volunteer work. My employer now says it would be best if I quit all of these activities because if they needed me, I would have to drop everything.

If I were a doctor or worked in security, I could see this rule being necessary, but the cafe is closed at night and closes early on the weekends! I also work with a very competent staff and have no concerns about leaving them alone. I was told I would need to sign a paper agreeing to essentially be "on call" in order to have the position. Can they do that? This is a salaried position.

A: Usually, with a "great" promotion comes great responsibility.

Yes, your employer can ask you to be on call as a manager (assuming, for simplicity's sake, that you're correctly classified as an "exempt" employee and aren't entitled to overtime). Before you sign anything, you and your employer need to reach an understanding of what exactly that entails, in clear, specific writing.

So do your due diligence and ask: Does being "available" mean reachable by cellphone, or within a certain distance of work? What kinds of situations do they anticipate needing you for? If you're not available, is that a firing offense? Is there a backup plan for when you're on personal leave? Historically, how often have managers needed to be called in? Talking to a current or former manager can give you a more realistic picture.

Although you might need to shuffle your priorities, you might not have to give up your other commitments entirely. Find out if they can spare you on occasion if you're called in to the cafe unexpectedly to respond to an after-hours alarm, fill in for a sick worker or appease an irate customer. The friend you keep books for may be fine with rescheduling; the people you volunteer for on Wednesdays might not.

Finally, you'll have to examine what your outside commitments give you - a creative outlet, a social life, a bit of extra income? - and stack that against what the new position offers: more money, more security, a better negotiating position for your next job?

It's like sitting in the emergency exit row on a plane: If you're unwilling or unable to assist others in an emergency, you're free to decline, but you don't get the bonus legroom.

• Miller has written for and edited tax publications for 16 years, most recently for the accounting firm KPMG's Washington National Tax office. Ask her about your work dramas and traumas by emailing wpmagazine@washpost.com. On Twitter: @KarlaAtWork.