The starting point is that the period out of service (the loss of time) corresponds to the period when the damage occurs until the vessel is ready to go back to service after completion of repairs.
The period during which the vessel has been deprived of income will usually include time lost during survey(s) of the damage, obtaining tenders, tank cleaning, deviation to the repair yard, waiting to commence repairs, docking and other measures necessary to carry out repairs and, not least, the time necessary for the repairs.
However, the time during which earnings are lost need not necessarily coincide with the period the vessel is actually out of service. The vessel may be on a time charter according to which the vessel shall be off-hire during the repair period and until she resumes service in a position not less favourable than where the casualty occurred. In such case, the vessel will be ready for service upon leaving the repair yard, however, without earnings until again being on hire as per the charterparty. It follows from Cl. 16-13 (a) that in such case, the insurer will be liable for time lost until the vessel can resume the voyage or the activity that it was engaged in under the charterparty in force at the time of the casualty, see further on recoverable loss of time after completion of repairs under 7.4.2 below.