the error message seems to be in line with what is explain in the documentation:
> Automatic data type conversion is implemented between numeric types. > A string that represents a number is not converted to a corresponding number. > There are special CAST functions that will convert values from one type to > another. http://doc.4d.com/4Dv16R6/4D/16-R6/4D-SQL-engine-implementation.300-3628406.en.html in other words, you can't expect 4D to implicitly convert numeric 2 to TIMESTAMP. besides, with an expression such as Select someDate - 2 it is unclear whether you want to subtract 2 years, months, days, hours, minutes, second or milliseconds. in addition to that, there is no way to express 2 days as TIMESTAMP. this is mentioned in the same URL, that 4D SQL does not support date constants where the month or day is 0. in other words, you can't use { d '0000-00-02' } to specify 2 days. and in case you are wondering, you can't use {t '48:00:00'} either, because a time constant that exceeds 24 hours throws a parser error. even if you find a way to specify 2 days in a way that the parser can understand, there is the fundamental problem that arithmetic expressions between VK_TIME (TIMESTAMP) values are type unsafe in 4D SQL. so I think the best option is to use {FN () } with an "Add to date" wrapper http://doc.4d.com/4Dv16R6/4D/16-R6/4d-function-call.300-3628422.en.html ********************************************************************** 4D Internet Users Group (4D iNUG) FAQ: http://lists.4d.com/faqnug.html Archive: http://lists.4d.com/archives.html Options: https://lists.4d.com/mailman/options/4d_tech Unsub: mailto:4d_tech-unsubscr...@lists.4d.com **********************************************************************
