Notice and time-bar periods in FIDIC 1999, FIDIC 2017 and NEC4 ECC: a clause-level reference and a deadline computation method

Contractual notice provisions can decide a construction claim before its merits are considered. A contractor that serves a notice of claim late can lose an entitlement to time or money that it would otherwise have proved. This note sets out, clause by clause, the notice, claim, response and time-bar periods in the unamended FIDIC 1999 and 2017 Red, Yellow and Silver Books and the NEC4 Engineering and Construction Contract. It states a simple method for converting those periods into calendar dates from an event date and an awareness date. It then discusses three practical complications: the condition-precedent status of the notice (including Uniform Building Contractors v WASA [2026] UKPC 2), the civil-law context of the GCC states (including the new UAE Civil Code in force from 1 June 2026), and the frequent amendment of standard periods through Particular Conditions. The full set of 142 rules is included as CSV and XLSX files. The same rules are implemented in a free online calculator: www.calim.ai/tools/notice-deadline-calculator. General guidance on the unamended standard forms, not legal advice.