1. Respect whatever decision the parents make regarding how they wish to spend the holiday. If they choose to skip it altogether, don't pressure or push them into doing something that you think they should do or attend.
2. Listen to their feelings without judgement or opinions, be available to help and support any decisions they may make about the day.
3. Realize that it doesn't matter how long it has been since they have lost their baby, in their mind, there will always be someone missing from the family gatherings.
4. Try not to have expectations regarding how the parents should act or behave on holidays should they choose to participate. Remind yourself that a lot of energy is being directed towards coping and making it through the day... they are doing the best that they can..
5. Ask them if they want to participate in preparations (food, set up, etc) and at what level they want to be involved.
6. Let them cry openly if they need to.
7. Be willing to discuss changes and/or variations in holiday rituals if it will make the day any easier for them.