Va. Code Ann. § 21-379

The sale of the lands for failure to pay such assessments shall be made at the courthouse door of the county in which the lands are situated, between the hours of 10:00 in the forenoon and 4:00 in the afternoon of the first Monday in February of each year. If for any necessary cause the sale cannot be made on that date, the sale may be continued from day to day for not exceeding four days, or the lands may be readvertised and sold on the first Monday in March succeeding during the same hours without any order therefor. If the county treasurer for any reason fail to make sale of any lands on the first Monday in February or March in any year, he may sell the same upon the first Monday of any subsequent month in the same year or any succeeding year after giving notice as required by law.