Daylite's databases are located in:
Hard Drive -> Library -> OpenBase -> Databases folder.

As of v1.7.4, databases can be located in a different folder. If you upgraded from v1.7.3 or below, your databases will still be located in Hard Drive -> Library -> OpenBase -> Databases.
However, if you made a fresh install of Daylite v1.7.4 and above, then your databases will be located in:
Hard Drive -> Users -> Shared -> Databases.obstorage

If you do not find your databases in any of those locations, check the contents of the following file to see where the databases could be located:
Hard Drive -> Library -> OpenBase -> Config -> DatabasePath

Databases.obstorage is package. To see the contents (where the actual databases are), do a 'Show Package Contents' in the Finder (using the contextual menu).

NOTE: These locations are not in your home folder. When you backup your database, please remember to backup your database as well.