I had the same experience in the last day or so. It seems to be caused in the field above, where you draw the area, if it’s not complete. Although i used polygon, and the vertices I used showed a shaded polygon, i did not put in the final point on top of the original, so it seems that the polygon was not properly described. When I did add the final point, the date and time field opened for input. I think that “circle” may not have that problem because a circle is defined only by center and radius, and there are default values for them as soon as you select circle.