Linux/Bash - Create Loop for "find" to output to a file - linux

Question

Apologies if this has been answered, I'm somewhat new to Linux but I didn't see anything here that was on target.
Anyway, I'm running this command:
find 2013-12-28 -name '*.gz' | xargs zcat | gzip > /fast/me/2013-12-28.csv.gz
The issue is that I need to run this command for about 250 distinct dates, so doing this one at a time is quite tedious.
What I want to do is have a script that will increment the date by 1 day after the "find" and in the file name. I really don't even know what this would look like, what commands to use, etc.
Background:
The find command is being used in a folder that's full of folders, each for 1 day of data. Each day's folder contains 24 subfolders, with each subfolder containing about 100 gzipped CSV files. So the find command is necessary 2 levels up from the folder because it will scan through each folder to combine all the data. The end result is that all the zipped up files are combined into 1 large zipped up file.
If anyone can help it would be hugely appreciated, otherwise I have about 250 more commands to execute, which obviously will suck.

Answer 1

What about something like this?
prev_date="2013-12-28"
for i in {0..250}; do
next_date=$(date -d"$prev_date +1 day" +%Y-%m-%d)
prev_date=$next_date
find $next_date -name '*.gz' | xargs zcat | gzip > /fast/me/$next_date.csv.gz
done
It should iterate through 250 dates like:
2014-08-27
2014-08-28
2014-08-29
2014-08-30
2014-08-31
2014-09-01
2014-09-02
2014-09-03
2014-09-04
2014-09-05

Answer 2

jmunsch's solution works very well if the dates are sequential. Otherwise you could do this:
(edited to replace dash characters with colons)
for folderName in $(find . -type d -mindepth 1 -maxdepth 1 )
do
date=$(basename $folderName)
dateWithColons=$(echo $date | sed "s#-#:#g") # this will replace - with :
find "$folderName" -name '*.gz' | xargs zcat | gzip > /fast/me/$dateWithColons.csv.gz
done