Days Between Calculator Dates

In recent times, days between calculator dates has become increasingly relevant in various contexts. Does the term "within 7 days" mean include the 7th day?. There's also the perennial question of whether the last day ends on the multiple of 24 hours from the time when the deadline was given, if it means midnight of that day, or closing time of that day, or what. And does "7 days" mean 7 calendar days, or 7 business days?

synonyms - One word substitutions for number of days? This perspective suggests that, words exist to label periods of time - like week which represents 7 days and fortnight which is used for a 14-day period. Are there other such words used for certain numbers of consecutive days? Building on this, word choice - What are the abbreviations for days of the week ....

It will be used in a tabular data program to show information about free work days of employed and each column can't have enought space to include full week day name. For "common form" I mean, what are the abbreviations that is more used in programs. 'In the upcoming days' - English Language & Usage Stack Exchange. In Australian English, "in the upcoming days" sounds strange.

"In the coming days" is acceptable but probably too formal, I agree with @BoldBen's comment that "In the next few days" is a better choice. meaning - Past few days or the past few days? - English Language .... So when we say 'the past few days' we mean the complete set of 'past few days', not just some of them, and which means this time phrase matches the tense.

In this context, do we use the phrase 'past few days' on its own? Highly unlikely, it lacks a sense of which days. Logical meaning of "within 30 days" compared to "in 30 or fewer days ....

Hospitals are penalized if a patient is readmitted within 30 days after the discharge date. Therefore if a patient returns in 30 or fewer days after discharge, it's a ding on the record. "Vacation days" or "days off" - English Language & Usage Stack Exchange.

In this context, in most organizations, vacation days are usable at the employee's discretion, up to a certain yearly limit. Days off is a more informal phrase that includes a variety of kinds of paid-not-to-work days, including sick leave, maternal/paternal leave, floating holidays, national holidays, etc. Vacation days are a subset of days off. In this context, two days "is" or "are"?

- English Language & Usage Stack Exchange. I have heard about the usage of "be" in specific situations like 2 days, 5 dollars,... For example: Two days ____ enough for us Should I use "is" or "are"? I see both of them are appropriate.

is there a difference between "last 2 days" and "past 2 days".