There are a few occasions when you may need to know which default Raiser's Edge database type you have. This is, for example, used by Importacular and Chimpegration to determine the default culture (date and number formats) that should be used (although these can be overridden).

It would be either UK, US, Canada or Australia (New Zealand is also available but I am told that is only used there). In the vast majority of cases, if you are based in one of these countries then you will have the corresponding format. This article is mainly aimed at organisations based in other countries. 
There is no really easy way of determining this other than by looking at constituent records. (There are a few differences scattered throughout the application but the ones described below are the easiest). 

1. If a constituent record has NIN field then it is UK.

2. If a constituent has a SIN number, then it is Canadian

3. If the constituent has and ID2 then it is Australian

4. If the constituent has an SSN number then it is US

Of course your organisation may have changed the value of that field to something relevant to you. In which case you will need to check in the Config, fields area of RE to determine what the value was originally: