Does it mean "through" or "up to"?
The word “until” appears to be ambiguous, especially when you pair it with a deadline. If a teacher tells you that you have until April 26 to turn in your essay, does that mean you can turn it in on April 26, or must you hand it over no later than April 25?
Alternatives to “Until”
Before we discuss dates, we need to talk about the four ways to write an alternative to “until.” Are you allowed to use “till,” “’till,” “til,” and “’til” instead of “until”? We can quickly cross “’till” off our list. It is considered nonstandard (1). On the other hand, “’til” is acceptable but “etymologically incorrect” (2). You may find yourself wanting to use “til.” According to dictionary.com (3), that word means “the sesame plant.” So you probably don’t want to use that if you mean “until”!
Now we’ve come to the word “till.” You may use this “till” in the same way as “until,” though expert Bryan Garner states that “till” is somewhat less formal than “until” (4). Interestingly enough, dictionary.com states that the word “till” was coined before “until.” “Till” appeared around 900 (5), whereas “until” arrived between 1150 and 1200 (6).
The Meaning of “Until”
"Until" can be ambiguous. You may need to use other words to be clear.
Now we must help a confused “Sentence Sleuth” blog reader named Judy, who wrote, “I recently missed an important deadline because I thought that the word ‘until’ included the date mentioned, whereas the writer’s intention was for the deadline to be the day before the date mentioned in his directions. For example, this particular direction was written, ‘The survey will be online for you to complete until May 1, 2010.’ When I went online on May 1, the survey was gone, and I was unable to complete it. Shouldn’t the direction have said one of the following, for example: ‘up to but not including,’ ‘through April 30, 2010,’ or ‘must be completed April 30’?”
This is a sticky question. An online dictionary (7) defines “until” as a preposition or conjunction that means primarily two things: “up to the time of” and “before (a specified time).” It gives examples such as “We danced until dawn” and “She can’t leave until Friday.” In the dancing sentence, the people stopped dancing when the sun began to rise. In the other sentence, the woman stays where she is on Thursday, but on Friday she goes somewhere else. In these two sentences, it seems clear when the people changed their activities.
With dates, however, the word “until” seems to be ambiguous. Let’s turn to the IRS site for help. Naturally! It explains, “April 15 of each year is the due date for filing your Federal individual income tax return, if your tax year ends December 31. Your return is considered filed timely if the envelope is properly addressed and postmarked no later than April 15” (8).
Therefore, taxpayers have until April 15 to stand in line at the post office and get the envelope postmarked. April 14 is fine; April 15 is fine; April 16 is not. The same online article addresses extensions and includes this instruction: “…you are allowed an automatic 2-month extension until June 15 to file your return and pay any tax due.”
So we’ve determined that the last day to file the return is April 15. A two-month extension takes us to June 15, which must include June 15. June 14 is fine; June 15 is fine; June 16 is too late.
It therefore seems that “until” plus a date includes that date. Let’s examine the essay sentence we mentioned at the beginning of this article: A teacher tells you that you have until April 26 to turn in an essay. Is it due on April 25 or April 26? You’d probably be safe turning in your essay on April 26.
Now let’s look at Judy’s question about the online survey. The directions said, “survey will be online for you to complete until May 1.” In this case, however, it’s not certain that “until May 1” includes May 1. If someone told you, “I will be in the office until Thursday,” you would likely assume the person will not be in the office on Thursday.
Judy was right to be confused!