Getting along with your former spouse or partner may seem impossible at times. But if you have kids, there are going to be special days where you will have to be together. Birthdays, holidays, graduations, weddings, and other occasions will be better for everyone if the two of you agree to get along.

Psychologist Shirley Thomas, author of Two Happy Homes: A Working Guide for Parents & Stepparents after Divorce and Remarriage, says the first year after a separation is always the hardest. “All family members are grieving,” she says. “It’s unavoidable.”

Younger children are especially vulnerable. Thomas says it might be best if you try sticking — as much as possible — to the family’s established routine during the first holiday season. “Small children won’t comprehend why things are different,” Thomas says.

She recommends you consider spending limited time together. “As you develop new patterns of celebrating,” she says, “you want your child to realize that, although things are different, they can still be happy.”

Emotions — anger, sadness, bitterness — will inevitably run high over the course of those first holidays. One good way to keep them in check is to make plans in advance and then stick to them. Thomas says.to decide in advance, for example, how long you are going to stay and then leave at the agreed upon time.

“You are going to be vulnerable,” she says. So it will be important to avoid spontaneity.

Consider avoiding alcohol too, Thomas says. “There’s usually more drinking, more alcohol, around the holidays,” she says. “Limit how much you drink. Otherwise, you might be less inclined to hold back.”

Once you’re through that first year, Thomas says, you can start establishing new ways of celebrating birthdays, Thanksgiving, and other events.

For some parents, being together always brings out the worst in either one or both. If you fall into that category, getting together could very well spoil the day for your children.

Psychologist Philip M. Stahl, author of Parenting after Divorce: Resolving Conflicts and Meeting Your Children’s Needs, says, “Self-awareness is very important. A lot of parents have it but all too many don’t. . Some parents, for whatever reason, remain in high conflict, and that’s not good for the kids.” If you and your ex can’t be in the same place with each other, Stahl says, you’re probably better off not getting together.

If both you and your ex are going to attend an event, it’s crucial that your children see that the two of you can get along. Thomas suggests thinking of your ex as a co-worker and then treating him or her accordingly.

“It should be a business relationship you strive for,” she says. “Think of how you relate to a co-worker. You are friendly, kind, and validating. But you don’t hug and you are not intimate. Mothers and fathers who are separated should not hug or kiss — that is not part of a business relationship.”