VOY条款中TURN TIME的扣除

May

请教大家，在VOY合同下，双方的约定如下：

Turn Time: 12 hours turn time at loading port and discharging port respectively, unless sooner commenced. If used, actual time used to be counted as laytime
Owners to give 12 hours turn time to charterers after tendering NOR for arranging cargo/documents, if sooner commenced all time used to count as LAYTIME.

合同没有约定船舶是否必须在LAYCAN时间内递交NOR。实际上，船舶早于laycan前抵达装港，并提前递交了 NOR。 但是租家只承认NOR有效，但是不接受12hrs TT提前起算，并提出抗辩如下：

1-1) 12 hours turn time
   
Firstly, we would like to point out that the key point is "whether Turn time can be commenced before layday", rather than "whether NOR can be tendered before the layday".

We agree that NOR can be tendered before layday, however, it does not equals to say that turn time shall be commenced before layday.

The foundation of this fixture is that the vessel is to arrive at the port of loading on and between 0000lt 5/mar and 2400lt 10/mar whereas the charterers/shippers is to have 12 hours as turn time for arrangment of cargo/docunents unless loading commences sooner. In fact, loading didn't commence sooner, then logically, 0000-1200lt 5/mar shall be deemed as turn time and shall not be counted as laytime.

请教大家，是否有合理的案例和相关规定可以支持抗辩租家的说法？顿首拜谢。