Learn French: Nous avons une réunion importante jeudi. - We have an important meeting Thursday.

Using just the day of the week (jeudi) means this is a one-time event happening this Thursday or on Thursday. If the sentence used le jeudi, it would mean the meeting happens as a recurring habit every Thursday.

Why isn't jeudi capitalized?

Unlike in English, days of the week and months of the year are not capitalized in French unless they are the very first word in a sentence.

Why is the word order réunion importante instead of importante réunion?

Most descriptive adjectives in French go after the noun they describe. While English says "important meeting", French places the adjective after, like "meeting important".

Why does importante have an 'e' at the end here?

Adjectives must match the gender of the noun they describe. Because réunion is a feminine noun (which we can tell from the feminine word une), we add an 'e' to the masculine word important to make it feminine.