Which regional rules of lent fasting or holy days of obligation should a Catholic follow? If I'm Catholic Argentinian by birth and citizenship and reside in Argentina, then the only thing to check is if I'm Eastern Catholic or Roman Catholic.
If I'm

Roman Catholic,

French in nationality and citizenship by birth,

but I recently renounced my French citizenship temporarily

to apply to some other citizenship say of Country X

and have yet to reapply for French citizenship because I don't yet have time

but I intend to reapply for French citizenship

and I reside in Germany, then



Which set of holy days of obligation will I follow? (France, Germany, Country X, a certain intersection, a certain union)
Which lent fasting rules will I follow? (France, Germany, Country X, a certain intersection, a certain union)
How do the answers above change if I reacquire my French citizenship?

Of course I'm not asking specifically about France, Germany and Roman Catholicism (This question extends to Eastern Catholicism and whatever is full communion with Roman Catholicism). I'm asking in general:

Which diocese/region/country/whatever do Catholics (I'm asking for roman catholicism, but you can answer eastern or other full communion's if you want) fall under for purposes of holy days of obligation or lent, do when they have dual or renounced citizenships or when they reside in a country that is not of their citizenship?


Related:
Are Filipino Roman Catholics required to not have meat on all Fridays of Lent?
Google calendar for catholic holdiays/holy days of obligation?
The rule for fasting is &quot;when in Rome, do as the Romans do.&quot; This is exactly the case where that saying derives. Where you are on the particular day determines whether you must abstain or fast regardless where you are from.
A typical occurrence for this would be in parts of the United States when St. Patrick's day falls on a Friday in Lent. Some bishops especially where the population has Irish heritage will dispense from the obligation to abstain from meat. It's entirely permissible for one to cross diocese boundaries to be able to have meat on that Friday.
Holy days of Obligations bind based upon where one has &quot;domicile&quot; (or quasi-domicile), which basically means based upon where one primarily resides and intends to return if absent. If you move to a new country and intend to reside there long term, you must follow the local rules for Holy Days. If you visit a country, you follow your home region's rules. See Holy Days of Obligation