# I bought something two days ago - quick question about logic

I have a question to do with language and logic that my mind is having trouble with. Please, try to explain it to me. It is both an English problem and also a problem to do with my native language.

Here is an example:

If I bought something two days ago. (e.g. Monday, so today is Wednesday) I can't say during Wednesday that I haven't bought anything for two days.

This is because I skipped just one day, and I can still buy something today, right? So I would say it in a way which makes it more logical for me: I haven't bought anything for one day.

Here is another example:

If I was at a club on Monday, and today is Wednesday, I would say I haven't been to that club for one day, since today I can still go there. However, I notice most people will express this differently, which in my opinion is illogical.

They say: "I haven't bought anything for two days" OR "I haven't been to that club for two days," meaning that the last time they were there was two days ago. How logical is this? Imagine you come to that club on Wednesday, having been there on Monday, and say to the same barman you saw there on Monday that you haven't been here for two days. He would be shocked: "What? are you stupid? You only missed one day here."

As in the case of the first question, "I haven't purchased anything for two days" should be used only if you last purchased something on Monday and today is Thursday, in my opinion, because we should not count Monday, when you bought something.

• If you book a tour that starts on Monday (say 3pm) and finishes on Wednesday (say 10am), it lasts for less than 48h, i.e. less than 2 days. But it would often be described as '3 days, 2 nights', because it spans (parts of) 3 calendar days. Likewise, the common usage of "haven't been there for 2 days" allows that you went there 2 days ago, like your Monday-Wednesday example. Commented Mar 18, 2017 at 9:44
• On the other hand, "haven't bought anything for 2 days" sounds to my ear like you didn't buy anything for the two days prior, so if you bought something on Monday and it's now Wednesday, you have bought something within the last 2 days, but you haven't bought anything for one day. Commented Mar 18, 2017 at 9:48
• ... Here, the problem arises because the English word 'day' is ill-defined (used in different ways). This is perhaps more easily seen with 'a month is 28 days'. Well, February, at least, usually has 28 days. And then there's "I'm 38 years old. I'll be 39 tomorrow." Commented Mar 18, 2017 at 9:48
• English is not logical; its usage has evolved; there are conventions. Each of the question's examples (with Lawrence's) are subtly different. Commented Mar 18, 2017 at 9:49
• so should I say I havent bought anything for two days or one day on Wednesday if I last bought something on Monday Commented Mar 18, 2017 at 9:54

I don't think it is so much a question of logic as precision. There are times when you want to be or are expected to be precise, and others where the reverse is true. I'll use "smoke" as in "smoke a cigarette" as the example, because I think it makes the point slightly better. The word "anything" in your first example is an unnecessary distraction, and I don't agree that the barman will look askance at you in the way you suggest.

If you say to me on Wednesday that you haven't smoked for two days, I may ask you to specify whether you last smoked on Sunday or Monday. Or I may simply be satisfied with the information that you haven't smoked for what you (or I) consider to be a significant length of time.

So if you want to make sure that your interlocutor understands that you are being very precise you will use since, as in

I haven't smoked since Monday.

Otherwise, if the need for precision is not at the front of your mind, there is nothing wrong with saying

I haven't smoked for two days.

• To me this is an interesting example of how people often need to see that their question is not so much about using the language correctly as being aware of the different choices they have. The words you choose express the view of a situation ("reality") that you want to project. Commented Mar 18, 2017 at 11:10