(a) Length of period. Where the assessment of any tax imposed by this title has been begun or made within the period of limitation properly applicable thereto, such tax may be collected by levy or by a proceeding in court, but only if the levy is made or the proceeding begun:
The period so agreed upon may be extended by subsequent agreements in writing made before the expiration of the period previously agreed upon. The period provided by this subsection during which a tax may be collected by levy shall not be extended or curtailed by reason of a judgment against the taxpayer.
(b) Date when levy is considered made. The date on which a levy on property or rights to property is made shall be the date on which the notice of seizure provided in Section 40-29-26 is given.