Calc; Cannot add time units to date

Calc; Cannot add time units to date

[Allen Li]

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Example repro:

1. emacs -Q
2. C-x * *
3. t N
4. ' 1.5hr RET
5. +

Expected:

1:  <2018-03-22 Thu 02:30>

Got:

1:  <2018-03-22 Thu 01:00> + 1.5 hr


Emacs  : GNU Emacs 27.0.50 (build 7, x86_64-pc-linux-gnu, GTK+ Version
3.22.28)
 of 2018-03-19
Package: Calc

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Re: Calc; Cannot add time units to date

[Robert Pluim]

Allen Li <darkfeline@felesatra.moe> writes:

> Example repro:
>
> 1. emacs -Q
> 2. C-x * *
> 3. t N
> 4. ' 1.5hr RET
> 5. +
>
> Expected:
>
> 1:  <2018-03-22 Thu 02:30>
>
> Got:
>
> 1:  <2018-03-22 Thu 01:00> + 1.5 hr

Hmm, Iʼm not convinced thatʼs meant to work. Could you point me at a
section of the Calc manual that describes that?

As an alternative, you can use

1h30

to specify the time, but I suspect you knew that.

Robert

Re: Calc; Cannot add time units to date

[Allen Li]

On Thu, Mar 22, 2018 at 2:36 AM, Robert Pluim <rpluim@gmail.com> wrote:
>
> Hmm, Iʼm not convinced thatʼs meant to work. Could you point me at a
> section of the Calc manual that describes that?

It's not in the manual, but I expected that it would work.  Is it
unreasonable to expect to be able to add time units to dates?

Re: Calc; Cannot add time units to date

[Noam Postavsky]

On 22 March 2018 at 13:38, Allen Li <darkfeline@felesatra.moe> wrote:
> On Thu, Mar 22, 2018 at 2:36 AM, Robert Pluim <rpluim@gmail.com> wrote:
>>
>> Hmm, Iʼm not convinced thatʼs meant to work. Could you point me at a
>> section of the Calc manual that describes that?
>
> It's not in the manual, but I expected that it would work.  Is it
> unreasonable to expect to be able to add time units to dates?

I think the point is that 1.5hr is not a time unit from Calc's point of view.

1.5hr + 1.5hour doesn't add together either.

Re: Calc; Cannot add time units to date

[Allen Li]

That's because hour is not a time unit.  hr is a time unit:

1.5 hr + 0.5 hr = 2. hr
1.5 hr + 30 min = 2. hr

(You need to press u s to simplify the units for the second example,
but this does nothing for the date arithmetic that is the subject of
this bug report.)

On Thu, Mar 22, 2018 at 1:16 PM, Noam Postavsky <npostavs@gmail.com> wrote:
> On 22 March 2018 at 13:38, Allen Li <darkfeline@felesatra.moe> wrote:
>> On Thu, Mar 22, 2018 at 2:36 AM, Robert Pluim <rpluim@gmail.com> wrote:
>>>
>>> Hmm, Iʼm not convinced thatʼs meant to work. Could you point me at a
>>> section of the Calc manual that describes that?
>>
>> It's not in the manual, but I expected that it would work.  Is it
>> unreasonable to expect to be able to add time units to dates?
>
> I think the point is that 1.5hr is not a time unit from Calc's point of view.
>
> 1.5hr + 1.5hour doesn't add together either.

Re: Calc; Cannot add time units to date

[Robert Pluim]

Allen Li <darkfeline@felesatra.moe> writes:

> That's because hour is not a time unit.  hr is a time unit:
>
> 1.5 hr + 0.5 hr = 2. hr
> 1.5 hr + 30 min = 2. hr
>
> (You need to press u s to simplify the units for the second example,
> but this does nothing for the date arithmetic that is the subject of
> this bug report.)

The way I read it, hr and min are units, and 't N' produces a
date. The documented way to add a time to a date is with '1h', which
works fine.

Robert

Re: Calc; Cannot add time units to date

[Noam Postavsky]

On 23 March 2018 at 04:32, Robert Pluim <rpluim@gmail.com> wrote:
> Allen Li <darkfeline@felesatra.moe> writes:
>
>> That's because hour is not a time unit.  hr is a time unit:

Ah, thanks, I was unaware of this.

>> 1.5 hr + 0.5 hr = 2. hr
>> 1.5 hr + 30 min = 2. hr
>>
>> (You need to press u s to simplify the units for the second example,
>> but this does nothing for the date arithmetic that is the subject of
>> this bug report.)
>
> The way I read it, hr and min are units, and 't N' produces a
> date. The documented way to add a time to a date is with '1h', which
> works fine.

Right, but it would be reasonable to unify the time units with dates.
If someone is looking for an elisp task...