Progress Clause in Contracts

Under most forms of standard Construction Contracts in Australia ’the Contractor must plan to achieve PC by the Date for PC’.

What do you think the Contractor should do under the following circumstances:

1. The Contractor’s Date for PC is different from the PM’s.
2. The Contractor knows that realistacaly the Date for PC can not be achieved.
3. The Date for PC has come and gone, but the Works are not complete

Thanx