bash – compare between the ubuntu shell script twice

I am working on a shell script that will do some things if the current time is between 19:00 and 1:00.
so I'm getting the current time that way

    current time = $ (date +% H% M% S);

and I convert the format starttime and endtime like this

    start time = $ (date -d 19:00 & # 39; +% H% M% S & # 39;);

endtime = $ (date -d 01:00 & # 39; +% H% M% S & # 39;)

so I make this condition to check if the current time is between 19h and 1h

num1 = $ (($ starttime- $ currenttime))
num2 = $ (($ endtime- $ currenttime))


if [ $num1 -lt 0 -a $num2 -gt 0 ];
then
echo "the current time is between 19:00 and 01:00"
other
echo "the current time is not in the range"
Fi

so if the current time is

8:00 p.m.

the value of num1 will be

190000 – 20000 = -1000

and the value of num2 will be

010000 – 20000 = -10000

so the condition will not apply because num2 always less than zero
please help how can I make real comparisons