<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def check_valid_ad_range(date):
 """ Checks if the english date is in valid range for conversion """

    if date < values.START_EN_DATE or date > values.END_EN_DATE:
        raise ValueError("Date out of range")
    return True