You are resident in the Republic of Ireland (ROI) if your ROI presence amounts to:
Presence of not more than 30 days in a tax year is ignored for the purposes of the 280-day test (s 819).
You are present for a day if you are present at any time during the day.
If you are resident and domiciled in the ROI, you are liable to Irish income tax on your total income from all sources, i.e., your worldwide income.
You are regarded as ordinarily resident in the ROI for a tax year if you were resident in each of the three immediately preceding tax years. You cease to be ordinarily resident when you have become non-resident for the three immediately preceding tax years (s 820).