Under Article 8 of the Kuwait Civil Code, all legal deadlines and time limits are calculated using the Gregorian (solar) calendar, unless a specific law states otherwise. This is the same calendar used internationally, so contract deadlines, limitation periods, and procedural timeframes are all counted in standard calendar days, months, and years.
This is practically significant for expats because it means there is no ambiguity when calculating notice periods in a tenancy agreement, a payment deadline in a contract, or the time limit for filing a legal claim. You count days and months in the same way you would in Europe, North America, or most of the world.
However, be aware that certain matters governed by Islamic law — such as some family law or inheritance issues — may refer to the Hijri (lunar) calendar. In those cases, the specific law applicable to that subject will indicate which calendar applies.
Practical advice: When drafting or reviewing contracts in Kuwait, always express deadlines in clear Gregorian calendar dates (e.g., "31 December 2025" rather than a number of days from an ambiguous start point) to avoid any potential dispute. If a deadline in your contract falls near a public holiday, confirm with a lawyer whether that affects the deadline's validity.
This is general legal information, not legal advice. For advice on your specific situation, consult a lawyer licensed in Kuwait.