When dates are fixed; the charterparty will state, for example, “lay/can 25/30th April”. The abbreviation ‘lay/can’ means that the ‘laydays start 25th April, cancelling date 30th April’. This means that the ship must arrive on or after 25th April and before 30th April. The charterer can refuse to load if the ship arrives before the first date, in fact the cargo may not be available. If the ship arrives after the cancelling date (or often after 16:00 on the cancelling date), the charterer is at liberty to cancel the ship and find another vessel to carry his cargo. This would prove to be a useful option if the freight rates had fallen since the charter was fixed and if the charterer were therefore able to obtain a cheaper ship; however, the converse is not necessarily the case: if a ship is late arriving and rates have risen in the interim and if the charterer confirms that the ship is still wanted, then the owner must proceed with the charter.
Shipowner calculates the cost of the proposed voyage by means of the voyage estimate and compares it to the anticipated freight to decide whether the voyage will be profitable. It is important that the owner knows how long the intended voyage will take, as the calculations are based on income per day, hence a delay may make the difference between a profitable or a loss-making voyage.