it is a bill where due date is at the time of expiry of maturity time

That would depend on the maturity

If it's a whole life policy, there is no specific maturity date. Please check if your policy is a whole life one.

A call date is a date on which a callable bond may be redeemed before its maturity.

Yield to maturity assumes that the bond is held up to the maturity date. This is a disadvantage. If the bond is a yield to call , it can be called prior to the maturity date. Thus, the ivestor should sell the callable bond prior to maturity if he expects that he will earn higer return by doing so (in other words when yeild to call is higher than held to maturity).