Parents searching for these sorts of educational yet fun games for Christmas will be better off if they find one or two products that have quality activities spanning several grade levels. That way everyone in the house can use the same resource, and there will always be brand new activities available each year. Before purchasing any product it is important to see if there are enough activities available at each skill level so they can be used several times during December and over the long Christmas vacation.
Many sites offer a single month at a time. That works okay since people only print one month at a time. Downloads are usually in Word, Adobe, or Excel. Which you use depends on which software you are comfortable with. If you know Excel best then get an Excel calendar. If you are very good with Word, there are formats available which can be adjusted on the screen. It takes some practice to add notes to any template, but it's not too bad with practice.