One problem that I face often is I have to create a directory with new version of files based on a previous directory. The convesion is to use the current date 20141125 followed by an letter 'a'. I wanted to script this out instead of doing it manually.
Obtaining the current date is easy:
date "+%Y%m%d"
This should yield the date of the form YYYYMMDD.
The next part is obtaining incrementing a letter. Here are two ways of doing it. The first uses the 'tr' command. The second uses bash's Brace Expansion.