Thanks for the report, and sorry for the slow reply.
Axel Kielhorn writes:
>> Am 30.05.2020 um 14:40 schrieb Axel Kielhorn <org-m...@axelkielhorn.de>:
>>
>> Hello,
>>
>> according to the manual, there is a special column type for column view
>>
>> ‘est+’ Add low-high estimates.
>>
[...]
>
> There was a bug report in 2014:
>
> Date: Tue, 16 Dec 2014 11:45:21 -0500
> Message-ID:
> <CAG2CFAaaFUyM5MJRfYxJ=kjnqmS=ub54rx3nvtsgdmcyhq-...@mail.gmail.com>
> To: emacs-orgmode@gnu.org
> Subject: [O] Bug: est+ not working,
> or perhaps under-documented [8.2.10 (release_8.2.10 @
> c:/Users/yhluc00/emacs/share/emacs/24.4/lisp/org/)]
>
> With a reply and a patch by Nicolas:
[...]
> Proper syntax is simply
>
> :Effort: 4-12
>
> But this gives:
> Invalid duration format: "4-12“
>
> Here is the patch:
>
> Fix low-high estimates c1558d34d Nicolas Goaziou
> <m...@nicolasgoaziou.fr> 16.12.2014, 23:53
I see the same thing on my end as well, using your example and the
example from the message you linked to:
--8<---------------cut here---------------start------------->8---
#+COLUMNS: %40ITEM(Task) %12Effort(Estimate){est+}
* Estimate
** Little Thing
:PROPERTIES:
:Effort: 1.0-5.5
:END:
** Big Mess
:PROPERTIES:
:Effort: 8.0-30.0
:END:
--8<---------------cut here---------------end--------------->8---
It looks like the fix from the above commit (c1558d34d) was later broken
by the transition to the org-duration library in Org 9.1, specifically
7e8cf5f4c (Use Org duration library, 2017-02-08).
