Luc / errors and problems / java, oracle / ORA-01722: Invalid Number Caused by to_char 04/09/2013 This might be caused by running to_char on a timestamp like this: to_char(dp.calc_date, ‘dd/Mon/yyyy hh:mi:s’). Try just returning the date without trying to convert it first. More about this error here. Share this:ShareClick to share on LinkedIn (Opens in new window)Click to share on Twitter (Opens in new window)Click to share on Reddit (Opens in new window)