System.FormatException: Input string was not in a correct format.

Sir, I am using following SELECT command for a query in aspx page:

SELECT Equipt, Shed    
FROM ERfailures WHERE Date >= '4/1/2012' AND Date <= '1/31/2013' AND loco_type = '3-Phase' AND classification = 'Loco'

Issue is, when i have cahnge the query as below

SELECT Equipt, Shed    
FROM ERfailures WHERE Date >= '1/1/20132' AND Date <= '1/31/2013' AND loco_type = '3-Phase' AND classification = 'Loco'

Issue is, when i have cahnge the query as below It is not working and generated an error as "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.FormatException: Input string was not in a correct format." Please help.