This expression, including a stipulation as to the number of hours in a day has given rise to some uncertainty. On one interpretation, for example, the charterer could be allowed to spread their 24 available hours across a number of days according to the habitual length of the working day in the relevant port. The definition of ‘working day’, on this interpretation, is therefore changed to take account of the concept of ‘working hours’ as well, and there is nothing to say that the hours have to be consecutive or interrupted only by excepted days. ‘Working Days of 24 Consecutive Hours’ and ‘Working Days of 24 Running Hours’ The courts have also considered the correct meaning of the expressions ‘working days of 24 consecutive hours’ and ‘working days of 24 running hours’ These have generally been found to mean a full 24-hour period without interruptions arising out of the length of the working day but excluding days such as Sundays and holidays on which work is not normally done. Clearly, these expressions will give rise to considerably less confusion than those which may be interpreted by reference to the number of working hours in the day at the relevant port. ‘Running days’ The words ‘running days’ are deemed to mean the same as ‘consecutive days’. The expression ‘running days’ would appear, in practice, to have little to distinguish it from ‘days’ on its own in so far as it will mean any day including Sundays and holidays unless excluded expressly or by custom. Now that we have established that it is not necessarily obvious what is meant by a ‘day’ or a ‘working day’ or a ‘running day’, it will be clear why many charterparties do not rely simply on the use of those words. It is, in particular, very common to find abbreviations such as SHINC (Sundays, holidays included) or SHEX (Sundays, holidays excluded) and variations on that theme. These are discussed in Chapter 3. However, if the calculation of the amount of time allowed is simply a function of the number of days of a particular type specified, then once the type of the day has been identified it can easily be established how much laytime is available. However, particularly in the context of dry cargo, laytime often has to be calculated not only by reference to the type of day but by reference to the quantity of cargo worked. In dry cargo charterparties, therefore, the laytime is usually determined by dividing the total cargo loaded by an agreed loading/discharge rate per day. As the actual amount of cargo loaded is not known until loading is complete, the exact amount of laytime is not known when the charterparty is fixed. For example, if 30,000 mt of cargo is loaded, and a loading rate of 5,000 mt per day for the vessel is agreed, the laytime will be 6 days for loading. Different rates may be agreed at the loading and discharge ports to reflect the cargo-handling ability of those ports. The above rate is a rate for the whole vessel. A vessel will have many holds which may be of different sizes. If all the holds are loaded simultaneously, the smaller holds will be completed first. However, the charterer would still be required to load at a rate of 5,000 mt per day, even though he may be loading fewer holds. It may get to the stage where all holds but one have been loaded. The charterer will still be required to load the final load at a rate of 5,000 mt per day, which will be impossible. To avoid this problem, which particularly arises on vessels with different-sized holds, a charterer can agree a rate per workable hatch per day. With an empty vessel of 5 holds, at a rate of 1,000 mt per day per workable hatch, the laytime for the vessel is calculated by dividing the amount the largest hold will contain by the daily rate. The largest hold should be completed last, and the formula recognises this. Example: A ship has 5 holds, the largest of which has 8,000 mt capacity. The smallest hold has 3,000 mt. With a discharge rate of 1,000 mt per workable hatch per day, the laytime is 8 days (8,000.;.1,000) If a rate of 5,000 mt per day was agreed for the same vessel to load 30,000 mt, the laytime would be 6 days. At first, the load rate would be the same as 1,000 mt/workable hatch/day. However, after 3 days, the smallest hold would be full. Then 5,000 mt must be loaded into only 4 holds. This is equivalent to 1,250 mt per workable hatch per day.