Laytime (or lay days) may be defined as the period of time agreed between the parties during which the owner will make and keep the ship available for loading and/or discharging without payment additional to the freight payment. It is a paramount duty of the shipowner to make the ship available for the charterers, in accordance with the terms of the charter party, at the agreed place and conversely, it is the duty of the charterers to make the cargo available and bring it forward to the ship for loading. The length of time allotted under the terms of the contract for the purpose of loading or discharging of the vessel is called laytime. Where laytime is exceeded (in other words the charterers have delayed the vessel in loading and/or discharging beyond the time stipulated for this purpose) then that will amount to a breach of the charter party and the contract may call upon the charterer to pay to the shipowner liquidated damages known as ‘Demurrage’. Should the charterer load or unload the cargo in a period which is shorter than the agreed lay days, he may be entitled, under the terms of most dry cargo charter parties (but not tankers) to a rebate, i.e. a ‘reward’ which is known as ‘despatch money’. The manner in which the total amount of laytime available to the charterers depends upon the wording of the charter party. In a tanker charter, for example, the time allowed is invariably expressed in “running hours”. This means that once the time starts to count there are no exception for holidays or bad weather. In many dry cargo charters, especially where the commodity is one which would be damaged by being wetted by rain, it is quite usual for the time allowed to be described as weather working days. This means that if, once time has started to count, bad weather prevents the berth from loading/discharging, that time does not count. It is important to note that even if the ship is waiting off the berth and the bad weather prevents work on ship(s) on the berth in front of the vessel concerned, time ceases during the time of the bad weather. It can be said that the expression “weather working day” describes the type of day it does not refer to work on that particular ship. In charter party where Sundays and holiday are excepted (SHEX) it is of course possible that the charterers will work during these periods and the parties will negotiate how this is dealt with. It may be SHEX “even if used”, or “if used actual time used to count” or “half actual time used to count”. All these factors plus any delays through mechanical breakdowns, strikes etc have to be taken into account when calculating demurrage (or despatch).