Learn English – “Prodigal” vs. “spendthrift”

The New Oxford American Dictionary has the following note.

For complex historical reasons, prove developed two past participles: proved and proven. Both are correct and can be used more or less interchangeably: this hasn't been proved yet; this hasn't been proven yet. Proven is the more common form when used as an adjective before the noun it modifies: a proven talent (not a proved talent). Otherwise, the choice between proved and proven is not a matter of correctness, but usually of sound and rhythm—and often, consequently, a matter of familiarity, as in the legal idiom innocent until proven guilty.

When used in reference to time, date almost exclusively refers to a specific 24 hour period that begins at midnight and ends at 11:59pm. When used this way, the date will be specified with a year (CE or BCE), the name of the month, and the number of the day within that month. The day number is a positive whole number that may be used in ordinal form (first, second, third, etc.) The name of the weekday is rarely referenced when referring to a date.

When setting up an appointment, you typically use the term 'date' if the appointment is a long time away or in a formal business setting. When making appointments with friends, especially if they are happening within one week's time, you would use the term 'day'.

You ask a friend "What day do you want to have lunch?" The receptionist at your doctor's office will ask you "What date would you like to have your next appointment?"