Confusing phrases: I was to go. vs I was to have gone.

[Classic]

I am confused about the following phrases. Please help me.

1. I was to go.
2. I was to have gone

Please provide the completed details of above sentences and grammar structure.

[Mister Micawber]

.
I can well imagine that they are often used synonymously; however:

1. I was to go tomorrow, but my flight has been cancelled.
2. I was to have gone yesterday, but my flight has been cancelled.
.
_________________
Native English teacher at Mister Micawber's

[Classic]

Excellent examples, which are self explanatory. Could you please suggest me intermediate / advance grammar web links.

[Mister Micawber]

.
These are some I use:

http://www.uottawa.ca/academic/arts/writcent/hypergrammar/
http://www.ucl.ac.uk/internet-grammar/home.htm
http://grammar.ccc.commnet.edu/grammar/
.
_________________
Native English teacher at Mister Micawber's