checking the gaps in intervals

Hi dear community,

Have probably quite simple task but cannot find the solution,

Imagine the table A with 2 columns start and end, data type is date

start          end
01 dec.     10 dec
11 dec.     13 dec
17 dec.     19 dec
.....

If I have interval, for example, 12 dec-18 dec, how can I determine
that the interval cannot be fully covered by values from table A
because of the gap 14-16 dec? Looking for solution and unfortunately
nothing has come to the mind yet...

Thanks,
Anton