Va. Code Ann. § 16.1-69.17:1

Any district court judge of this Commonwealth may qualify at any time after receiving his commission and before the expiration of thirty days after the commencement of his term of office; but if he fails to receive his commission until after the commencement of his term of office, he may qualify within thirty days from the date of receiving such commission. If a judge fails to qualify as above provided, his office shall be deemed to be vacant.