The NEC3 does not give a definition of ‘day’; however in one contract there is a separate definition given for ‘Working Day’ which specifically excludes weekends and Bank Holidays. In a delay situation with Delay Damages applicable since there is no definition of ‘day’ but there is of ‘Working Day’, it would make sense to me to assume that Delay Damages cannot relate to weekends since the Contractor has been prevented from working weekends, which had he not the Delay Damages may not have been applicable. Your view please.
The argument here is tenuous to say the least.
In secondary Option X7: delay damages at clause X7.1 it uses the words “for each day” and not the words “for each Working Day”. Therefore there’s no argument to be constructed for calculating damages based on a Working Day as those words are not used in X7. Presumably they also don’t appear in Contract Data part one instead of the standard wording that says the “amount per day”? Unless use of the term Working Day elsewhere in the contract is specifically in the context of calculating delay damages I don’t think it is relevant. A day, is a day, is a day i.e. including weekends, bank holidays and Christmas / Easter shut downs - it means literally every day.
As Neil quite rightly states, a definition in one document or clause is not necessarily interchangeable with that in another.
Your definition for ‘Working Day’ possibly relates to the working hours approved by the local authority under a Section 61 agreement for noise, thereby restricting certain types of working to specific times or days.