30 Del. C. § 1103: Resident individual defined.

A resident individual of this State means an individual:

(1) Who is domiciled in this State to the extent of the period of such domicile; provided, however, an individual who is present in a foreign country or countries for at least 495 full days in any consecutive 18-month period, and during such period of 18 consecutive months is not present in this State for more than 45 days, and does not maintain a permanent place of abode in this State at which the individual’s spouse, children or parents are present for more than 45 days, and is not an employee of the United States, its agencies or instrumentalities (including members of the Armed Forces) shall not be considered a resident of this State during such period; or

(2) Who maintains a place of abode in this State and spends in the aggregate more than 183 days of the taxable year in this State.