My numbers turn into # signs, when I move to the next block

[Gogetter72]

I am having trouble with inputing dates within the cells. When I move to the
next block, the numbers turn into # signs. What do I need to do to fix this
problem?

 

[David Biddulph]

Make your column wider, or your font smaller, or choose a date format that
is shorter (such as dd/mm/yy instead of dd/mm/yyyy or dddd dd mmmm yyyy).