Interpreting ‘days’ and ‘months’ in construction contracts: a summary

Posted: 10/03/2025

The correct calculation of time periods under a construction contract is crucial. A miscalculation by even a day could result in a contractor’s legitimate claim being refused by an employer due to lateness, or an employer being forced to pay an application which, in any view, is overvalued. The calculation of time periods is also fundamental to adjudication. As is well known, a referral or adjudicator’s decision issued late will render a decision unenforceable.

It is therefore vital that those in construction are familiar with how ‘days’ and ‘months’ operate within these calculations. This article seeks to provide a helpful summary on these key concepts. 

How does a ‘day’ feature in calculations?

Given the importance of calculating the time periods for payments, it is surprising there was limited guidance on the meaning of ‘day’ in the construction context. This was finally provided by the case of Elements (Europe) Ltd v FK Building Ltd [2023] EWHC 726 (TCC). 

The parties’ contract was based upon a JCT Standard Building Contract, 2016 edition, with bespoke amendments. Under clause 4.6.3.1 of the contract, Elements needed to make payment applications no later than four days prior to the relevant interim valuation date (IVD). The IVD was the 25th of each month, or nearest business day in that month.

Elements emailed a payment application to FK Building at 10:07pm on  21 October 2023. This left the court with a straightforward issue to decide: was a payment application validly made on 21 October if made at that hour?

The court answered the question in the affirmative, explaining that English law does not work in fractions of a day. In effect, if a contract requires a party to complete an act by a fixed date, said party has until 23:59:59pm on the final day to complete this action; in other words, the whole ‘day’ to complete the step. 

However, if the contract had provided that an action needed to be completed by a particular time of day, this would have prevailed over the general rule that a party has the entire day to complete the action.

How does a ‘month’ feature in calculations?

The definition of ‘month’ was considered recently in My Contracts Limited v 74 Hamilton Terrace Freehold Limited [2024] EWHC 2896 (TCC). My Contracts agreed to complete façade remedial works, for which it had accepted it was liable. The contract was based upon a JCT Design and Build, 2016 edition, with bespoke amendments. It included an article 12, paragraph 6, which broadly provided that 74 Hamilton would have no further claims in respect of the façade, unless these were notified ‘not later than four months after the date of the contract’. 

The parties entered the contract on 2 March 2023, and on 3 July 2023, 74 Hamilton purported to give a notice, notifying My Contracts of further cost relating to the façade remedial works. My Contracts contended that this notice was out of time and should have been served by 2 July 2023, commencing a Part 8 claim for a declaration on the validity of the notice, following an unsuccessful adjudication.  

The parties agreed the common law position: the notice should have been provided by 2 July 2023 under the ‘corresponding date rule’. Broadly, the rule provides that where a period of month(s) is stated for an act to be completed, the period will expire on the same date in the final month of the period, or if there is no such day (eg 30 February), it will expire on the final day of that month (ie 28 February). However, 74 Hamilton made two arguments as to why the rule should be disapplied in its case.

First, as the final date for service of the notice was not a ‘business day’ (2 July 2023 being a Sunday), it should take effect on 3 July 2023. Second, the four-month period included four public holidays and therefore, it should be extended accordingly. In support of this second point, 74 Hamilton cited clause 1.5 of the contract, which stated:

‘Where under this contract an act is required to be done within a specific period of days… [w]here the period would include a day which is a Public Holiday that day shall be excluded.’

However, the court was unconvinced by either argument, holding that the notification was late and of no effect. As to the ‘business day’ point, the court held simply there was no basis to interpret ‘day’ to mean ‘business day’. Indeed, the fact that ‘business day’ was a defined term and used elsewhere in article 12 was a powerful factor against interpreting the use of ‘day’ in article 12 paragraph 6 as meaning ‘business day’.

Regarding the exclusion of public holidays, it held that clause 1.5 was not engaged as the clause stipulated that public holidays were excluded from a period stated in days, whereas the period in question was expressed in months. As such, there was to be no extension to the period.

A trap for the unwary

While the court was considering a bespoke article, its reasoning in respect of clause 1.5 applying only to periods stated in days appears equally applicable to stipulated monthly periods within the various JCT contract forms.   

This presents a particular trap for the unwary in relation to the due date for the final payment, and provisions for the issue of a final certificate. In various JCT forms, the date for both of these events is often set by reference to a period of months from the trigger event.

Often where the contract provides for a final certificate, it also includes provisions that this certificate is conclusive if not challenged in time. It is therefore vital to understand if the issue of the final certificate has been timed correctly. Equally, a party will need to first establish the correct due date, in order to calculate both the final date for payment and the final date for the issue of a payless notice, should it wish to issue one. 

A failure to calculate either date correctly could result in a party being bound to pay the sum stipulated in the final certificate, with no avenue to challenge its value.

Position under the Housing Grants, Construction and Regeneration Act 1996 (HGCRA)

It would be remiss to not also consider the default provisions of the HGCRA. Section 116 provides that public holidays are to be excluded from calculations. However, section 116(2) simply states: ‘Where a period would include…’. The provision is not limited to just periods of days.

While this appears to be broader than the common JCT clause 1.5 at face value, and would exclude public holidays from any monthly periods, it is likely to be of little practical difference. This is because currently all time periods stated in Part II HGCRA, and the Scheme for Construction Contracts (England and Wales) Regulations 1998, are stated as a number of days.

Summary

In summary, the following points can be drawn from the above cases:

• the common law does not recognise ‘fractions’ of a day;
• a party will have the entire day to complete a required action;
• a monthly period will expire on the corresponding date in the final month of the period, or if there is no corresponding date, the last day of the final month;
• a monthly period ignores public holidays, and it is irrelevant whether the final date falls on a ‘business day’; and
• some JCT contracts contain time periods which are stated in days and others in months; clause 1.5 is likely to only apply to the periods stated in days.

However, it must be remembered that it remains open to contracting parties to vary the above default positions by an express contract term. This fact was expressly acknowledged by the courts in both above cases.

As a final note, while the JCT has now rolled out its 2024 suite of contracts, there are no amendments to standard clauses 1.5 or 4. Therefore, the above cases would appear to apply equally to the new JCT editions currently being published.

Return to news headlines