I have set up navvsion for one company and Axpta for another. In the navvision i could have the journal voucher numbering set for a date range. eg. 12000001 to 1299999 with the start period 1/1/12 and end period 31/12/12 and 13000001 to 1399999 with the start period 1/1/13 and end period 31/12/13.
In the navvision, What this does is if I try to pass a journal in 2012, it will take the number starting 12xxxxxx. If I try to pass a journal voucher for 2013, it will take the number 13xxxxxx. This is very useful in keeping track of the numbering.
However in Axapta this feature of date range is not there. Thus if i pass a journal in 2013, it will take the next numbering, thus leaving a gap. Eg. voucher 1 to 10 in 2013 and 11th voucher for 2012. This causes confusion sometimes.