Prepositions – Does ‘Until [Date]’ Mean ‘Before That Date’?

ambiguitydatesprepositionsrange-inclusion

What does until mean in the following?

You need to deliver this product within 2 days (until August 18, 2011)
to meet your deadline and get paid.

Does this mean that I have to deliver the product by 23:59 on 17 August 2011 or 23:59 on 18 August 2011? The order time is 21:04 on August 16 2011.

Best Answer

My default reading of that would be that you can deliver the product at any time on the 18th of August, 2011 and still be considered to have met your deadline.

If the deadline were 23:59 August 17, it would have been stated as "(before August 18, 2011)".

I will also note, though, that most people will consider "the end of the business day" rather than "the end of the day" to be the cutoff time, so you might be considered late if you turn it in after 17:00, if that's when your client normally closes their offices.