Raishuu ni natta or naru?


I found the following sentence in _Minna No Nihongo_ :

> すみませんが、出張は来週になったと伝えていただけませんか
>
> _Sumimasenga, Shucho wa raishu ni natta to tsutaete itadakemasenka?_  
>  'Please, Could you tell him that the business trip will be on next week.'

Shouldn't it be 'shucho wa raishu ni naru' instead of 'natta' since shucho
will take place in next week?




The business trip is in the future, but the postponement of the business trip
（来週になった）occurred in the past, therefore the usage of past is correct.

