In Australia our financial year starts in July. Excel is set up to work with calendar years and we need to do some date gymnastics to have our reports start in July. Here is a hack for Custom Lists that can make some things better in Excel.
Make Your Own Lists like January, February etc
When you drag a cell with January in it with the fill handle (the small cross at the bottom right corner of the cell), Excel creates a series with February and March etc. This is quick and useful. It also works for days of the week. Eg drag a cell with Monday in it to get Tuesday, etc. This is an example of a custom list.