TimeSpan.Humanize does not behave as expected

[cryptiklemur]

WIth the following timespan of: 296.19:32:06.8100684

Using the following code:

string createdAt = timeSpan.Humanize(10,  minUnit: TimeUnit.Day, maxUnit: TimeUnit.Year);

I would expect the output to be: Something around 9 months, etc. But instead, it shows 2 days

[hangy]

Apparently not implemented, yet:

Humanizer/src/Humanizer/TimeSpanHumanizeExtensions.cs

Line 16 in cd5bbac

private const int _lastTimeUnitTypeIndexImplemented = (int)TimeUnit.Week;

Humanizer/src/Humanizer/TimeSpanHumanizeExtensions.cs

Line 113 in cd5bbac

case TimeUnit.Month:

[cryptiklemur]

Ah, well that is disappointing

[JonPSmith]

Yes, disappointing as no warning that this would happen.

I would have preferred a NotImplementedException rather than silently failing

[aloisdg]

Indeed I think it should be loud too. Better, it should be implemented! 😉

@JonPSmith Could you look into it? Thank you ☺

[JonPSmith]

Hi @aloisdg,

I have participated in a few projects, but I'm on two contracts at the moment so I don't have the time at the moment.

[aloisdg]

@JonPSmith No problem!

[redwards510]

Here's a simple test case to illustrate this bug.
var result_is_6days = TimeSpan.FromDays(370).Humanize(1, null, TimeUnit.Month, TimeUnit.Second, ", ");

Apparently it breaks going from TimeUnit.Week to TimeUnit.Month

[reinhardtb]

Hi -

I would like to contribute the fix for this issue to the project, though I can't seem to complete a pull request back into the dev branch. Would someone please get into touch with me to get this going (sorry, it's my first time :) )?

Thanks,
Reinhardt

[hangy]

I think your PR #604 could be fine. Just check the failing unit tests. It appears that they currently validate that the cases you want to fix do not run, so it's probably just a matter of correcting the current unit tests and expanding them to check for the newly supported changes.

[reinhardtb]

Cool - thanks for the feedback - will check out those unit tests!

[akamud]

Before we start writing any code, we should see how we should convert days to months/years.

A month has 28 days (4 weeks) or 30 days?
A year has 365 or 366 days?

Or should we use the exact value (1 month = 30.436875 days) and round it?

[clairernovotny]

The challenge with anything date related is that the year and locale often matter. You can use the TimeZoneInfo class to get the rules for how many days a particular year has (leap year) or however many days a month has (per month). But it's hard to do that w/o context.

Not sure the right answer here.

[JonPSmith]

I had a come up with a solution for the project I was on. I found it was really hard to do when staying in TimeSpan but I made it work for DateTime.

I found the various answers to the stackeoverflow question Date difference in years using C# useful. In the end worked out the years using dana's answer.

I hope that helps.

[hazzik]

Bare TimeSpan would not make any sense without reference to a fixed point in time. E.g. 366 days is just 366 days.

But 366 days ago can be 1 year or 1 year and a day ago depending on a context.

We need to make sure that we distinguish between bare TimeSpan and TimeSpan as a difference of 2 dates & times.

For a bare TimeSpan we could implement a fuzzy logic, saying that 366 days is about 1 year ago.

[akamud]

I like the idea of using fuzzy logic for bare TimeSpan

[aloisdg]

I think the fuzzy logic is good enough. It could be more precise, but I guess thats fine.