How to add hour to date

Question

I am trying to get the date with a variable year, month and day but an specific hour.

Let me explain myself. I have a variable called $date using the next format

date=$(date +%Y%m%d)

Which gives me 20130814 (for today). Just as I want for that variable

But I need another variable, let's call it $date1 who will have something like $date but an specific hour. I mean, taking the example above, 2013081405. I need to add that 05 to $date every single day, that means that for tomorrow I will have 2013081505 and so on

Answer 1

The bash syntax for that would be:

date1="$(date +%Y%m%d)05"

Answer 2

Why can't you try

$date1 = $date."05";