9 Del. C. § 4660: Short period of limitations.

The bond resolution authorizing the issuance of bonds, or any notes issued in anticipation of said bonds, may be contested only if:

(1) Such obligations are authorized for a purpose for which the County is not authorized to expend money;

(2) The provisions of law which should be complied with at the date of the publication of such resolution are not substantially complied with, and an action, suit or proceeding contesting such validity, is commenced within 20 days after the date of such publication; or

(3) Such obligations are authorized in violation of the Constitution of this State.