dates/times are stored internally in database fields in compressed format, and SQL select statements do the translation for you, even displaying in locally set display variation. No such shortcut for insertion/update though. you'll need to find out the name of the specific ToDate or ToTime function of your specific database engine. each database engine (oracle, mysql, mssql, etc.) stores and handles dates/times differently, and have their own function to handle such. an example insert for a ficticious database engine would be something like

insert into this_table (ToDate("17-07-2007");
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of course the actual format of the date you pass in is database engine specific, using particular delimiters and honoring (or not) your locale setting for date display.