When someone says "I need x by Friday", I usually take it to mean they want x in their hands when Friday begins. However, when that same person says "I need x on Friday", I understand them to mean they want x no later than the end of the day Friday.

What about "I need x for Friday"? Is "for" in this context synonymous with "by" or "on"?

Do other people understand "due by" and "due on" in the same way I do? Is there a common consensus?


2 Answers 2


I think two of these are more-or-less interchangeable, but one is not. They also lend themselves to different levels of clarification and specificity in their request, and a different order to the information presented.

"Due by" implies that there is a set time of when it is due. "The sales report is due by 12pm on Friday." The day something is due follows the time, which is given more importance. The time can be stripped and the sentence will still work, one just loses the precision of the request.

"Due on" places more importance on the day something is due, and not so much the time. "Your membership fee is due on Friday." A specific time can be added but it would follow the day/date.

"Due for," however, is more about the person or event something is due for, and not so much when it is due. "Is that essay due for Mr. Green's class today?"

  • While I agree that "due for" usually refers to a person and event and not the time something is due, I received an email recently where someone said "we need this for Thursday". When "for" is followed by a temporal noun, what is the precise meaning? Given your example with 'Mr. Green's Class', "due for" seems closer to "due on", putting more emphasis on the date than the precise time. Would that be your interpretation?
    – Delyle
    Nov 18, 2015 at 21:32
  • I feel my answer may be getting a little far into the realm of opinion, but hopefully it still works. When saying something is due for Thursday, I am inclined to believe that whatever is due is needed for Thursday. Be it a speech that will be given that day, a list of names/set of data for something, or what-have-you. Whatever is due will be used then. So, one could say that the report is due on Wednesday by 11:30 for Thursday. Where "on" gives the broad time, "by" gives the specific time, and "for" gives the reason or event.
    – Zach W
    Dec 15, 2015 at 19:39
  • I love it when they say something like "due by Friday and no late applications will be accepted." Please people, add a time when you say "due by".
    – Virgo
    Jul 6, 2018 at 1:32

I see no substantive difference between these three. Even with "due by," I think it would be ambiguous as to whether someone wanted x by the beginning or the end of Friday. Personally, I would use "due by" to cover all three and would take it to mean something like "up to and including Friday." "Due on" Friday seems strange because it could imply that it is due only on that day and couldn't be handed in sooner, and "due for" sounds idiomatically strange, with "for" seeming like a wrong prepositional choice to me.

  • Anywhere I've ever worked, when something is due on/by Friday, it means by the close of business on Friday. Otherwise it is stated: This is due 9 a.m. on Friday. "Due for" is used more in the following kind of sentence: I haven't had a raise in five years; I think I'm due for one. Or: We're due for some rain this weekend. Nov 18, 2015 at 2:58
  • I interpret "due for Friday" to mean that there is a meeting on Friday, and that I should complete the assignment before Friday.
    – LexieLou
    Nov 18, 2015 at 3:12
  • @Steven Littman -- Yes, true about that use of "due for" -- though that's not the sense being discussed here ("due" has a somewhat different meaning in that context). Nov 18, 2015 at 14:26
  • @ Lexielou -- Sounds strange to me, but interesting nevertheless. Nov 18, 2015 at 14:27

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