The ornamental design for a christmasadventcalendar with shutters, as shown and described.
FIG. 1 is a perspective view of a Christmas advent calendar with closed shutters showing my new design;
FIG. 2 is a perspective view thereof, wherein the shutters are in an open state;
FIG. 3 is a front view of FIG. 1;
FIG. 4 is a front view of FIG. 2;
FIG. 5 is a back view of FIG. 1;
FIG. 6 is a left side view of FIG. 1; and,
FIG. 7 is a right side view of FIG. 1.
The broken lines showing of the numbers 1-24 is included for the purpose of illustrating unclaimed subject matter and forms no part of the claimed design.