Whenever a guardian shall collect any principal or interest belonging to his ward, he shall have sixty days to invest or loan the same, and shall not be charged with interest thereon until the expiration of such time, unless he shall have made the investment previous thereto, in which case he shall be charged with interest from the time the investment or loan was made: Provided, That if by due diligence any guardian is unable to loan any principal or interest belonging to his ward within the time aforesaid, and it becomes necessary for him to apply to the circuit court for authority or direction concerning such funds, such guardian shall not, pending a hearing of the matter, be chargeable with interest on the funds in his hands uninvested, unless the court or judge otherwise order.