# How to specify dates with “detri”?

45 views

### Wuzzy

Apr 28, 2016, 5:30:50 PM4/28/16
I have trouble making sense of the official definition of “detri”.
It states:

> x1 is the date [day,{week},{month},year] of event/state x2, at
> location x3, by calendar x4.

The notes state:
> (time units in x1 are specified as numbers separated by pi'e or are
> unit values massified with joi); See also cmavo list de'i, djedi,
> jeftu, masti, nanca, tcika.

I just want to specify a date, but the definition is not really helpful.
The brackets are confusing, what are they supposed to mean?

How do I specify …
… a day, month and year?
… a day (ONLY a day)?
… a week?
… a month?
… a year?
… a day and a month?
… a day and a year?

What do I do if I want to specify a date of a calender which works
differently (i.e. the day/week/month/year scheme does not
apply or at least it does not apply well)?

The only thing which seems be be clear is “li pa pi'e pa pi'e pa pi'e
pa detri” which can only mean “day 1, week 1, month 1, year 1”.

What does “li pa detri” mean?
Day 1? Week 1? Year 1?
What does “li pa pi'e pa detri” mean?
Day 1, week 1? Day 1, month 1? Day 1, year 1? Month 1, year 1?
What does “li pa pi'e pa pi'e pa detri” mean?
Day 1, week 1, month 1? Day 1, month 1, year 1? Week 1, month 1, year 1?

You get the idea.

Basically, the problem is that the definition is confusing / not clear
on the meaning of each of the numbers which are supposed to be
seperated by a “pi'e”.

Even something relatively simple like clearly (that is,
without other interpretations) specifying day/month/year seems to be
impossible. Saying “li pa pi'e pa pi'e pa detri” could mean
day/month/year, day/week/year or even day/week/month. Or did I
misunderstood the definition?

I hope you can help me, but it seems the way the definition is written
now makes it basically pretty useless (to me, at least). :-(

### Bruno Panasiewicz

Apr 28, 2016, 5:45:31 PM4/28/16
to mriste

28 kwi 2016 23:30 "'Wuzzy' via lojban" <loj...@googlegroups.com> napisał(a):
>
> I have trouble making sense of the official definition of “detri”.
> It states:
>
> > x1 is the date [day,{week},{month},year] of event/state x2, at
> > location x3, by calendar x4.

Hm. I always thought the definition to say, "year, {month, day}", or something like that.

So the more or less used format is the ISO one: YYYY-MM-DD, and the language allows «xo'e» for unspecified numbers. Not sure about the week thing though.

Have a look at this discussion of a proposal for a new system, loi lerfu tcita detri:

https://mw.lojban.org/papri/Proposal:_loi_lerfu_tcita_detri;_the_final_word_on_the_problem_of_dates_and_times%3F

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### Jorge Llambías

Apr 28, 2016, 5:55:08 PM4/28/16

I think your question is not how to specify dates with "detri" but how to specify dates with "li". Specifying dates with detri is easy. For exampe "lo detri be lo nu mi jbena" specifies the date I was born. You can fill the x1 of "detri" with anything that refers to a date. For example "la'o gy Tuesday, April 28 2016 gy cu detri lo cabdei" is perfectly fine.

How to specify dates with "li"? First, ignore what the definition of detri says, then use common sense. For example, I would say "li 1969-07-20 cu detri lo nu lo remna cu pa re'u stapa lo lunra" (with "-" pronounced "pi'e"). But that's just one possible convention. As long as it's clear which convention you're using there shouldn't be a problem. It's not as if any language forces you to use always the same convention, and neither should Lojban.

If you're using a different calendar, you choose a convention appropriate for that calendar.

mu'o mi'e xorxes

### Gleki Arxokuna

Apr 29, 2016, 2:31:24 AM4/29/16
"Lojban for Beginners" has this solution:
• If there is only one number, it is the day e.g.  li pano is ‘the 10th’.
• If there are two numbers, they are the day and month e.g.  li pano pi’e pare is 10/12, or ‘the 10th of
December’.
• If there are three numbers, they are day, month, year (not month, day, year, as in the American
convention) e.g.  li repa pi’e ze pi’e pasoxaso is 21/7/69—the date of the first moon landing

You get the idea.

Basically, the problem is that the definition is confusing / not clear
on the meaning of each of the numbers which are supposed to be
seperated by a “pi'e”.

Even something relatively simple like clearly (that is,
without other interpretations) specifying day/month/year seems to be
impossible. Saying “li pa pi'e pa pi'e pa detri” could mean
day/month/year, day/week/year or even day/week/month. Or did I
misunderstood the definition?

I hope you can help me, but it seems the way the definition is written
now makes it basically pretty useless (to me, at least). :-(

### Wuzzy

May 3, 2016, 12:07:34 PM5/3/16
Am Fri, 29 Apr 2016 09:30:43 +0300
schrieb Gleki Arxokuna <gleki.is...@gmail.com>:
> "Lojban for Beginners" has this solution:
> • If there is only one number, it is the day e.g. li pano is ‘the
> 10th’. • If there are two numbers, they are the day and month e.g.
> li pano pi’e pare is 10/12, or ‘the 10th of
> December’.
> • If there are three numbers, they are day, month, year (not month,
> day, year, as in the American
> convention) e.g. li repa pi’e ze pi’e pasoxaso is 21/7/69—the date
> of the first moon landing

Why isn't this (or something similar) in the official
definition (or in the notes)? :-(

I now had 3 different answers, each of them (more or less)

For insance, you say, the order is year, month, day, another one say its
day, month, year because of ISO. Official definition also uses the day,
month, year ordering.

It's nice you all try to explain how detri is used “in actual usage”,
but it seems that “actual usage” varies to a great extent, so it is not
really useful. :-/

IMO we need a clear and well-defined OFFICIAL definition for detri, not

According to your answers so far, I can't even safely make sense out of
something like “li pa pi'e re pi'e ci detri”, because you don't seem
to even agree on the ordering. :-(

### Gleki Arxokuna

May 3, 2016, 12:18:52 PM5/3/16
2016-05-03 19:07 GMT+03:00 'Wuzzy' via lojban :
Am Fri, 29 Apr 2016 09:30:43 +0300
schrieb Gleki Arxokuna <gleki.is...@gmail.com>:
> "Lojban for Beginners" has this solution:
> • If there is only one number, it is the day e.g.  li pano is ‘the
> 10th’. • If there are two numbers, they are the day and month e.g.
> li pano pi’e pare is 10/12, or ‘the 10th of
> December’.
> • If there are three numbers, they are day, month, year (not month,
> day, year, as in the American
> convention) e.g.  li repa pi’e ze pi’e pasoxaso is 21/7/69—the date
> of the first moon landing

Why isn't this (or something similar) in the official
definition (or in the notes)? :-(

Because the official "definitions" was more like a draft. There appeared noone like Cowan to publish a dictionary.

I now had 3 different answers, each of them (more or less)

Well, Lojban for Beginners and "lerfu detri" don't contradict each other. Otherwise, yes.

There is also one more solution: not to use {detri} at all. You may use {jednpa} etc., {de'i'u}...

For insance, you say, the order is year, month, day, another one say its
day, month, year because of ISO. Official definition also uses the day,
month, year ordering.

It's nice you all try to explain how detri is used “in actual usage”,
but it seems that “actual usage” varies to a great extent, so it is not
really useful. :-/

IMO we need a clear and well-defined OFFICIAL definition for detri, not

According to your answers so far, I can't even safely make sense out of
something like “li pa pi'e re pi'e ci detri”, because you don't seem
to even agree on the ordering. :-(

### guskant

May 4, 2016, 2:12:17 AM5/4/16
to lojban

Le mardi 3 mai 2016 16:07:34 UTC, Wuzzy a écrit :

Why isn't this (or something similar) in the official
definition (or in the notes)? :-(

I now had 3 different answers, each of them (more or less)

For insance, you say, the order is year, month, day, another one say its
day, month, year because of ISO. Official definition also uses the day,
month, year ordering.

It's nice you all try to explain how detri is used “in actual usage”,
but it seems that “actual usage” varies to a great extent, so it is not
really useful. :-/

IMO we need a clear and well-defined OFFICIAL definition for detri, not

Those different answers gave you some different examples of convention, which are not suggestion for official definition.
The official definition of {detri} does not restrict the form of x1 to one convention: x1 of {detri} is any sumti that can be a symbol for a time point; the applicable symbol is defined with x4.
The form of x1 depends on context, and you can specify the form with x4 or any additional items like {fi'o}, {noi}, {ti'o}* and so on if necessary.

(*Use of {ti'o} for that purpose is not officially suggested but I think it is enough applicable for specifying mapping of numbers to time points.)

According to your answers so far, I can't even safely make sense out of
something like “li pa pi'e re pi'e ci detri”, because you don't seem
to even agree on the ordering. :-(

The official definition for {detri} should not specify the ordering because {detri} has x4 by nature to specify the calendar that defines the system of mapping of symbols to time points. If you think the current definition is confusing, we need to add explanation of usage of x4, not restriction to the form of x1.

Le mardi 3 mai 2016 16:18:52 UTC, la gleki a écrit :

Well, Lojban for Beginners and "lerfu detri" don't contradict each other. Otherwise, yes.

No, as explained above, those are different conventions and not definitions of x1 of {detri}. They all can be used in different contexts. Because the context should be different between them, the universe of discourse is different between them, and therefore they cannot contradict each other.

There is also one more solution: not to use {detri} at all. You may use {jednpa} etc., {de'i'u}...

As explained above, you can stay with {detri} by declaring x4 of {detri}.  {jednpa} series and {de'i'u} series are all defined with {detri} and they can be expanded to {detri} form of the same meaning.

mi'e la guskant

### Gleki Arxokuna

May 4, 2016, 2:23:54 AM5/4/16
And breaking this thread to somewhat parallel. I think this might be a good place to post my conversation with la lojbab. that happened not long ago. Sorry for formatting.

Gleki:
> L4B uses an approach of specifying timestamps and dates using either {pi'e} or cmene.
> However, the official definition mentions some {joi} method:
> detri = x1 is the date [day,week,month,year] of event / state x2, at location x3, by calendar x4. (time units in x1 are specified as numbers separated by pi'e or are unit values massified with joi); See also cmavo list de'i, djedi, jeftu, masti, nanca, tcika.
> What is this "unit values massified with joi" method? I can't find its usage anywhere. How it was supposed to work?

Robert LeChevalier:
06/11/15
> I think that is referring to something like "5 djedi joi 11 masti joi 2015 nanca, which of course could be given in any order, whereas the pi'e method requires a standard order in order to know what units the numbers refer to.
> Actually that isn't completely true since someone could used mixed numbers and lerfu separated by pi'e:  5d.11m.2015n and you would probably know the meaning even if the terms were in a different order; but back when we first made the gismu, we had not yet virtually eliminated any difference in grammar between lerfu and namcu.
> There were a lot of people arguing for different orderings for the date components, and we wanted to have a method that could easily specify the ordering for those who wished to use a non-standard order, whatever the standard might have ended up.

Gleki:
>> 5 djedi joi 11 masti joi 2015 nanca
> not sure what you mean. {li 5 djedi joi 11 masti joi 2015 nanca cu detri} obviously doesn't parse.

Robert LeChevalier:
> How about if you just leave off the li?  Then you have three quantified sumti joined into one by joi

Gleki:
>You mean {lo djedi be li 5 ku joi lo masti be li 11 ku ...}? But then they can't fill detri1 because detri1 is a number.
>As for {5 djedi} it simply means "5 fullday intervals" that not necessarily go one after another, they can intersect.

Robert LeChevalier:
> We have cmavo that convert *anything* into a number. a sumti, a bridi, whatever.  So that would work too, using the Mex conversion cmavo.  mo'e can convert a sumti into a number; ni'e can convert a selbri into a number.
> (I have to admit that in our usage, we never said that "detri1 is a number", requiring conversion to a particular kind of construct. Rather, the place structure specifies what NORMALLY goes there, and if something abnormal goes there, one would pragmatically assume the proper type-conversion.  Thus pragmatically one would not need the conversion operator, but they are provided in case they are needed for formalism.)

>>As for {5 djedi} it simply means "5 fullday intervals" that not
necessarily go one after another, they can intersect.
>"not necessarily", indeed.  But implicit in joi is that they are in some (non-logical) way additively connected.  Which way is determined pragmatically, and when we came up with it, this was more or less a conventional pragmatics that made sense.
>An employee who is paid by the hour and works 5 cacra is not going to work 5 overlapping hours, and is unlikely to work 5 completely unrelated hours; the most common pragmatic interpretation is that they are consecutive hours.  Similarly with dates - there is no plausible meaning of 5 djedi in a date context that is other-than contiguous and consecutive, because that is what dates measure.
>(We did not put a lot of thought into this question, but largely presumed that all such matters would be resolved by pragmatic convention, which is also what pi'e requires/denotes.)

Gleki:

Robert LeChevalier:
10/11/15

--

### Pierre Abbat

May 20, 2016, 7:28:33 PM5/20/16
On Tuesday, May 03, 2016 23:12:16 guskant wrote:
> Those different answers gave you some different examples of convention,
> which are not suggestion for official definition.
> The official definition of {detri} does not restrict the form of x1 to one
> convention: x1 of {detri} is any sumti that can be a symbol for a time
> point; the applicable symbol is defined with x4.
> The form of x1 depends on context, and you can specify the form with x4 or
> any additional items like {fi'o}, {noi}, {ti'o}* and so on if necessary.
>
> (*Use of {ti'o} for that purpose is not officially suggested but I think it
> is enough applicable for specifying mapping of numbers to time points.)

What do you put between {ti'o} and {se'u} for dates? For that matter, what do
you put for operator precedence?

Pierre
--
li fi'u vu'u fi'u fi'u du li pa

### guskant

May 22, 2016, 11:04:55 AM5/22/16
to lojban, ph...@bezitopo.org

For example the following form seems to me reasonable:

ti'o nanca ce'o masti ce'o djedi (se'u) li 2016 pi'e 5 pi'e 22 detri lo nu mi ciska kei lo gugdejupu la gregoris

For operator precedence, I suggest using {ce'o} and {ve kanji}:

ti'o zo pi'i ce'o zo su'i ve kanji (se'u) li pa su'i re pi'i ci du li ze

though it is different from the example currently given in the corresponding BPFK section:
ti'o zo pi'i ce'o zo su'i porsi li pa su'i re pi'i ci du li ze
("x" and "+" is an ordered sequence) 1 + 2 x 3 = 7 (created for this, mi'e RossOgilvie, 16/6/10)

Maybe I should consult BPFK about my suggestion, but I don't think BPFK should give restriction on the usage of {ti'o}. I rather prefer that BPFK only suggests some possible examples of usage, and that users can freely invent any usage for their own purpose.

mi'e la guskant