Those of you who are the family photographer you often tend to be eliminated from history simply by not getting on the other side of that camera/phone camera. Every year on Christmas morning I set my camera up on a tripod, zoom out as much as possible and set my camera on a interval timer. (well as of last year I now use a remote to trigger my camera, thanks to my mother in law who gifted it to me!!) But if you don't have that, but you do have a DSLR camera let me walk you through using your interval timer. Now these directions are for a D700. But I'd imagine if you whip out your manual (or look up your manual online) you could find specific directions to using the one on your camera.
An interval timer allows you to set your camera to take X amount of shots every X seconds. You pick the X amount. Be sure to put your camera on auto focus so that something will be in focus when using your interval timer. On my D700 I have 3 options of auto focus. When I'm using my interval timer I like to set it on the top option (this allows the camera to auto detect what to focus on. While it doesn't always pick what I want, it usually gets a good portion of my images good enough for a good Christmas memory of us in our jammies on Christmas morning.)
Now hit the Menu Button (mine is located on the back of the camera in the top left corner)
On a Nikon D700 you can find the interval timer option under your "Shooting Menu" (on the side it's the one with the camera icon.)
To select interval timer shooting click your big circle button (the multi selector) to the right. (see image below)
Once you have selected interval timer, select start now, then you can set how many hours, minutes or seconds you want your images to be apart. I usually set the camera to take an image every 30 seconds. This will give me a good variety of images, but not give me too many to have to sort through later.
Now you get to select how many images your camera will capture. Here you can see I am picking 72. So 1 shot every 30 seconds 72 times will give me a little over 30 minutes (36 to be exact). The way kids tear through gifts on Christmas morning, that should be plenty of time, and usually we even have time at the end to sit there and smile for one last shot or two looking into the camera. Once you have that all selected move the multi selector to the right one more time, then hit the "OK" button on the bottom left corner of the camera. The camera will immediate take the first image, which is likely to be a dud since you are standing right in front of the camera, but that's okay you have 71 more great shots coming! HAPPY HOLIDAYS!
Here's an image we got last year. I hope you give it a go so you can be documented and part of history as celebrating Christmas morning with your family.