Question

Which words in the sentence are the complete infinitive phrase?

She was so tired that she forgot to announce the time of next week's meeting.

Answer 1

It's too announce the time's of next week's meetings!

Answer 2

She was so tired that she forgot to announce the time of next week's meeting.

to announce is the infinitive verb
and 'the time of next week's meeting' is the adverb clause that describes the verb.