c# - Syntax Error Converting DateTime From Character String -

i trying insert row in ms-sql table using following code

sqlcmdtext = "insert attendance(date, time_in, time_out, time_total, status,"; sqlcmdtext += "  is_late_in, is_half_day, is_early_out, user_id, remarks)"; sqlcmdtext += " values('@yestarday_date', 'na', 'na', 'na', 'absent', 'na', 'na', 'na', 52, 'done portal')"; sqlcmd = new sqlcommand(sqlcmdtext, sqlcon); sqlcmd.parameters.addwithvalue("@yestarday_date", yestarday); sqlcmd.executenonquery(); 

where yestarday string variable containing short date format "04/04/2011". tried passing datetime variable not work, same error below.

"syntax error converting datetime character string"

what format should use make work?

thanks.

use datetime.parse(yestarday)

sqlcmd.parameters.addwithvalue("@yestarday_date", datetime.parse(yestarday));