There is an art (and a science) to numerical precision that seems lost in software, writing and conversation. The trick to appropriate precision is understanding accuracy. This all falls under the banner of numeracy.
For example, I just received a confirmation of a cinema booking that gave the time of the film in HH:MM:SS format. The site lists programme times in HH:MM. They normally start trailers within a few minutes of the advertised time. To list seconds is an innumerate and false promise.
I sometimes receive notifications that I can expect a delivery in a 2-hour window such as "between 12:07 and 14:07".
To quote to the minute shows a failure of understanding of what an approximate range is, as well traffic and logistics.
It's a 2-hour window of imprecision. Quoting to the minute shows a deep lack of understanding. Quoting to 5-minute intervals is just about acceptable. To 10- or 15-minute is more appropriate significance. But honestly, in this case, to the hour is just fine.
Received a message telling me to expect a delivery "between 09:50am and 2:45pm". To their credit, they avoided quoting the estimated range to the minute (or to the second!), but the implication of quoting such limits to a precision of 5 minutes is nonsense given that the window of uncertainty is 5 hours.
When developing software systems, understand your domain and understand your users. Your users are human, so go with "between 10am and 3pm" to sound like you know what you're doing.
@kevlin At least 2:45 must be "most likely". There is always a non-zero chance it doesn't arrive at all due to "acts of god". Then again, giving legal disclaimers by sms seems unwise...
Sometimes though, the delivery is trying to uphold their part in a contract with some consequences involved. Sometimes, if you are not there, the package will be returned. Then precise times, if correct and if they matter, seem appropriate.
Kevlin Henney
Eivind Jahren