Client:
This has to be done with in 160 hours.
Me:
Seems doable

After maybe 100 hours of developing:
Client:
This is great and all but we decided to change the specs little (a lot) surely you can code this whole thing again in the rest of the time.

Welcome! :-)

@OutOfRange thanks :)

Holy what?!

Classic

Had this happen to me with a program for filling out a contract. Boss gave me the new contract and was like "Oh they just changed some text so you just need to adjust the printer file, should be done in two days".
Nope. Not at all. They also changed options on the contract so we had to redo the whole program; which took two weeks.

@jonii this is your boss fault, not your.

Guys, ALWAYS write a offer/contract of what the client's requests / specifications, the time estimation and the fee.
In this contract, there MUST be written that every change of the specifications will not be included in the current offer and, if the client really really want them, they will be defined in a separate offer.
(Obviously, the client must sign this contract)

This is the only way to protect yourself from such situation.
I can't understand why too many people don't do that...

My condolences

Oh my. It happens way to often. In requirements engineering this is expected. The client never knows what they want. Also, business strategies changes way to fast. I hate this so much. I hope you have a good contract that allows you accommodate new deadlines and costs.

@taglia my boss was cool about it that it took longer, because he realized it was his fault. Also we don't work for clients, it's all only programs for the company itself, that's why it's unneccessary to do such things. Eventhough I should start writing functional specifications more serious..

Mail him an official lookin statement saying it'll cost extra money and all that shit.

Most clients will believe the world is flat if you use offici language.