Conversion failed when converting date and/or time from char

Many thanks...
When i run the program have following error. Please help to find out the error.

Conversion failed when converting date and/or time from character string.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.Data.SqlClient.SqlException: Conversion failed when converting date and/or time from character string.