A lovely person gave me an idea years ago of combining sand tray and advent calendars. I finally found a product that I think works! Check out these options below and pre-order by September 7.
Square sand tray without miniatures - $45, ships in late September
House sand tray without miniatures - $75, ships in late September
Square advent sand tray with miniatures - $100, ships in November
House advent sand tray with miniatures - $130, ships in November