You’ve looked at your schedule, and see that you’re slammed. Then, you receive an email from a client requesting a change to an event proposal. Also, an attendee is wondering if they can call with questions about the program you’re putting on. Soon, your me-time has dissipated and you’re attempting to make the impossible happen.

It’s easy to give up your free time to do more work: After all, this is the life you signed up for. Phone calls throughout the day, meetings peppered throughout the week and incoming messages at all hours may have been a part of your work world from the beginning. But what you may consider compromise can quickly turn into sacrifice, forgetfulness or lack of follow-through—and it may not be worth it.

“Yes” is an important word in the event-planner’s vocabulary. But sometimes “no” is just as necessary. It can seem scary at first. What if you lose business or miss out on networking at happy hour? But avoiding saying yes 100 percent of the time is invaluable—and can lead to greater productivity, rejuvenation the next day and an overall excitement that can fall by the wayside when inundated with responsibilities.

When to Say No

Obviously, you can’t eliminate yes entirely—there are many things that must be done. So, prioritize your tasks. If you need most of the day to fulfill a work commitment, say no to that invitation to lunch. If somebody tries to pass their responsibilities on to you, it’s OK to tell them that it isn’t possible now.

When it comes to meetings, question how necessary it is for you to attend. If you are busy and can send an employee in your place to a meeting that is not high-priority, do it, and request the employee to take notes for you. When that’s not possible, explain that you’re busy and would appreciate having a summary of the meeting emailed to you.

For clients who expect you to make a change that simply can’t be made, politely let them know it can’t be done. Frame it apologetically, such as, “I’m sorry, but the venue won’t allow for a change, since the event is only a few days away.” It indicates that you want to take your client’s change into consideration, but that it simply isn’t possible.

When You’ve Already Said Yes

So, you accepted a lunch date with a friend, only to realize that a looming deadline is near. Say that you won’t be able to get together, and offer to reschedule. Most friends—especially those who work—will understand your time crunch.

Saying yes to clients, only to later realize you cannot fulfill a promise, creates an awkward situation. The potential backlash from bowing out can make planners nervous about changing their response.

If you’re absolutely positive you can’t make it, alert your client as soon as you can. Then come up with solutions you can deliver in the allotted amount of time. The client may be frustrated, but having other options available will lessen the impact of a no and demonstrate that you’re still committed to planning the best event possible. There’s always a possibility the client will pull out—especially if there’s nothing in contracts declaring they can’t—but it’s better to lose business through honesty than claim you’ll accomplish something and then fail to deliver.

Use Me-Time Proactively

If you fall victim to saying yes too often, it’s time to begin filling your calendar with hours you’ll take for yourself. Whether you turn off your phone at 8 p.m. or carve out a few hours to call a family member, knowing that you are free will lighten any potential guilt. By writing this time into your schedule, there’s no way you can double-book. Taking a moment for yourself can clear your mind and provide extra energy when you go back to work.