Hi Lera! Both you and the sentence are correct :) There are 2 correct versions of this phrase: 1) "The Slow Food movement was founded *on the day that an Italian journalist*..." 2) "The Slow Food movement was founded *the day that an Italian journalist*..." #1 sounds more formal when spoken aloud, like something out of a textbook. #2 sounds more casual and is closer to what you'd hear in everyday language. You could go one step further and remove the "that" to create an even more casual version: #3 "The Slow Food movement was founded *the day an Italian journalist*.." This is something you might hear in everyday conversation. Does this make sense? ~ Steph Teltz

You mean missing? If so, then the answer is no. : )

Technically, yes, "...was founded *on* the day..."; it cites a specific event/incident. But in everyday conversation, it's acceptable without the *on*.

The sentence is perfectly fine. "The day that... etc" tells us when the movement was founded.