Lojban Tutorial: Lesson 5

Lesson 5: Times, days, dates

One way to ask the question "What is the time?" is ''ma
tcika. We know that ma'' is the sumti
question word, so tcika must be
a selbri meaning "is the time", with the ti meaning "this event", or, in other words "now". The place structure of
tcika is

x1 (hours, minutes, seconds) is the time of state/event x2 on day/date x3, at location x4, by calendar x5

A full answer would obviously be very long-winded, but remembering the
Lojban convention that you miss out all the places after the last one
you really need, a typical exchange would be:

  1. ma tcika ti
  2. li vo
  3. "What's the time?"
  4. "Four"

Note the li, since we are talking about a number here. li vo
is short for li vo cu tcika ti—"four is the time of this

If we want to be a bit more precise, we need to use pi'e.
This is like pi, but doesn't need to keep the same value. In
normal counting, pi is a decimal point, in hexadecimal it's a
hexadecimal point and so on, but it never changes its value.
pi'e doesn't have that restriction, so we can
use it to separate hours from minutes. So an alternative answer to the
question could be

li vo pi'e mu
"Five past four."

or if you want to be particularly precise,

li vo pi'e mu pi'e pabi
"Five minutes and eighteen seconds past four."

Let's imagine, though, that the time is not five past four, but five
to four. We can still say li ci pi'e mumu (4:55) but we can also
say li vo pi'e ni'u mu. ni'u is the
Lojban minus sign (for negative numbers, not for subtraction)—what we
are saying is "4:-5".

For "half past four" you can also use pi and say
li vo pimu—4.5. I don't particularly like
this method, but it is perfectly good Lojban. If we are using numbers
for times, it is normal to use the 24-hour system, so 6 p.m. is li pabi (18:00).

Another possibility, is to use cmene for
hours, so "four o'clock" is la vocac., "five
o'clock" is la mucac. and so on. For 11 and 12
we need extra numbers. Fortunately
Lojban has these and more; the number system actually goes up to 16
(hexadecimal), so we have the extra numbers


Obviously for anything
other than talking about computer programming, the numbers 13-15 are
useless, but we can use 10-12 for hours. "Ten o'clock" is la daucac. "Eleven o'clock" is ''la
feicac.and "twelve o'clock" is la gaicac.''.

For "morning" and "evening" we can then add lir. and lec.,
meaning "early" and "late". So la mucaclir. is five in the

Exercise 1

What are the following times in Lojban?

  1. Nine o'clock
  2. Eleven o'clock in the morning.
  3. Two in the afternoon.
  4. Midnight.
  5. 9:25
  6. 12:15
  7. 14:30
  8. 17:50

If we want to give the time of an event, rather than just tell the time,
we need to fill in some more places. The second place of tcika is "state/event", so we need some way to show
that the sumti in this position is a state or an event,
and not a thing.

la daucac. tcika le mi klama

does not mean "Ten o'clock is the time that I go" (or come!), but "Ten
o'clock is the time of my goer," which is meaningless. We get round
this problem with the word nu, which
guessed—"state/event". This is called an "abstraction descriptor" (or
"abstractor" for short), other common descriptors being ka (quality or property), ni (amount) and so on (for a complete
list, see The Complete Lojban Language, p. 269). What nu does here is allow us to put a whole bridi into
a sumti place. It's usually written together
with the article (le or lo) but is actually a separate word. So what we want

la daucac. tcika lenu mi klama

(note that there is no cu here, since la daucac. is a

If "Ten o'clock is the time that I go" sounds
backwards, there are two ways you can switch it round. One is using
se, which swaps the first and second places of
the bridi.

''le nu mi klama cu se tcika la

means exactly the same thing. se is
co-incidentally is pretty much the same as Spanish "se", but is actually
part of a series along with te, ve and xe, which convert the first and third,
first and fourth, and first and fifth places. These aren't used so much
in sentences as se, but are often used in making
lujvo (compound words), as we'll see later in the course.

Still too long
and clumsy? Get ready for more Lojban tricks. It would be really nice
if klama had a place for the time of
going/coming, but it doesn't (after all, you wouldn't really want a
six-place selbri!).
To get round this problem of missing places, Lojban has a series of
"tags" of the class BAI. The one we want here is ti'u, meaning "with time". So we can now say

mi klama ti'u la daucac.

So why, you may ask, didn't I just say that in the first
place? I could have done, but then you wouldn't have found out about
nu and se! There is
more to this lesson than meets the eye.

Days and Months

The days of the week are also numbers, this time adding djed., from the ''gismu,
djedi'', meaning "day".
There is at present some disagreement about which day should be day one,
though. The original convention was to follow the Judeo-Christian
convention of taking Sunday as the first day, giving

la padjed.
la redjed.
la cidjed.

... and so on. However, in a meeting in 1992 it was
agreed that Monday be day 1, and Sunday be either 7 (la zedjed.) or zero (''la
nodjed.'') according to taste. Eventually, though,
people will use whichever system they prefer until one becomes
universally accepted. This may sound chaotic, but I have gone into this
point as a good example of how in Lojban a large part of the language is
"left to usage"—meaning that ultimately the language depends on the
way people choose to use it in practice. People are also free to work
out alternative conventions for cultures which do not use a seven-day
week, possibly adding to the name to make it clear; e.g. la padjedjung. could be the first day of the Chinese
ten-day week.

Months also use numbered cmene, adding mast., so January is ''la
pamast.'' and so on. Again, since there are twelve months,
we use the extra numbers, so October is ''la

Exercise 2

What are these days and months in Lojban?

  1. Saturday
  2. Thursday
  3. March
  4. August
  5. November
  6. December

Just in case you're interested, the words for seasons are:


for full definitions of these words, see the gismu list). If the seasons where you live don't
match this pattern, then you can easily create new
words. For example, the rainy season or monsoon could be
carvycitsi (from carvi,
rain, and citsi, season) or simply la carv. . Here are some I made up for fun to give
a better idea of the weather in the UK:

la lekcarv.
"the cold rain"—Spring
la mliglacarv.
"the warm (mildly-hot) rain"—Summer
la bifcarv.
"the windy rain"—Autumn
la duncarv.
"the freezing rain"—Winter

Joking aside, this shows two features of word-building in
Lojban: making cmene by losing the final vowel
(which we saw in Lesson 1) and creating lujvo,
or compound words. You actually need a pretty good knowledge of Lojban
to make up lujvo on the spot, but we'll learn
how to make simple lujvo later on in this


The gismu for dates is detri:

x1 is the date (day, week, month, year) of state/event
x2, at location x3, by calendar x4

Phew! Like tcika, though, most places of detri can be left out. The location is
only important if we're talking about radically different timezones, or
different planets, and the calendar is normally assumed to be the
standard Western one—if you want to use, for example, the Arabic or
Chinese calendars, you can put le xrabo or le jungo in the
fourth place (as always, context is important—in a discussion of
Islamic history we would probably assume that the Arabic calendar was
being used).

The tricky bit is the number in x1. Normally we don't
want to specify the day, week, month and year! To prevent
confusion, the following conventions are used:

  1. If there is only one number, it is the day e.g. li pano is "the 10th".
  2. 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".
  3. 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.

We can therefore say

li repa pi'e ze pi'e pasoxaso cu detri lenu lo remna cu pamoi klama le lunra
21/7/1969 is-the-date-of the-event a human first go (to) the moon

Here we have another case of abstraction with nu. Just like articles have the terminator ku (which is usually missed out), abstractors like
nu have the terminator kei. kei is not necessary in
this particular sentence, because the abstraction comes at the end, but
it would be necessary if there were other places after
x2—if, for example we wanted to emphasise that this was
the date in Houston (but not in Tokyo) we would say

li repa pi'e ze pi'e pasoxaso cu detri lenu lo remna cu pamoi klama le lunra kei la xustyn.
21/7/1969 is-the-date-of the-event a human first go (to) the moon (according to the time at) Houston

The kei here is important, as it is necessary to
stop the nu abstraction running into la xustyn., which would make the sentence say that a
person went to the moon from Houston—true, but not what we want. By
the way, if you're wondering why kei wasn't necessary in the tcika example, it
was because the cu marked the next word
as the main selbri.

Just as with tcika, we often want to put the event first—after
all in most languages we would normally say "My birthday is on the
fifteenth of August" rather than "The fifteenth of August is the date of
my birthday." We can manage this change by using place tags, e.g.

fe lenu mi jbena kei cu detri fa li pamupi'ebi
the-event I am-born is-dated 15/8

but it is easier to use se like this:

lenu mi jbena cu se detri li pamupi'ebi
the-event I am-born is-dated 15/8

And, as you probably guessed, there is a BAI tag for "dated": de'i (notice how BAI tags tend to be
similar to the selbri they suggest). So the
other way I can tell you my birthday is ''mi jbena de'i li

Question: If only one number is used with
detri, it is the day. So how do we say what year an event
happened without giving the day and month as well?

The gismu, nanca cannot be used instead of
detri, since it has the place-structure
"x1 is
x2 years in duration, by standard x3," i.e. it gives the length of an
event in years, not the year when an event happened. One way out is to
use a cmene for the year, so the year I am
writing this would be la pasososonanc.

Exercise 3—history quiz

Give the dates to answer these questions, using cmene for the years.

  1. lenu la kolombus. facki lo cnino gugde cu se detri ma
  2. la mexmet. dable'a la konstantinopolis. de'i ma
  3. lenu fraso jecyga'ibai cu se detri ma
  4. la marks. .e la .engels. ciska le guntrusi'o selpeicku ku de'i ma
  5. la muxamed. klama la medinas. de'i maVocabulary:;facki:find, discover

conquer, sieze ("war-take")
revolution ("government-change-force")
Communist ("work-govern-idea")
manifesto ("thought-book")


Apart from times and dates, this lesson has covered some important
points of Lojban grammar.

  • Some simple lujvo.
  • The descriptor for states and events, nu, and its terminator, kei.
  • Conversion—swapping round places—with se.
  • The BAI tags ti'e ("with time") and de'i ("with date").

Answers to Exercises

Exercise 1

  1. la socac.
  2. la feicaclir.
  3. la recaclec.
  4. la revocac.orla gaicaclir. (if you follow the convention that midnight is 12 a.m.)
  5. li sopi'eremu
  6. li parepi'epamu
  7. li pavopi'ecinoorli pavopimu
  8. li pazepi'emunoorli pabani'upano

Exercise 2

  1. la zedjed.
  2. la mudjed.
  3. la cimast.
  4. la bimast.
  5. la feimast.
  6. la gaimast.

Exercise 3

  1. la pavosorenanc.
  2. la pavomucinanc.
  3. la pazebisonanc.
  4. la pabivobinanc.
  5. la xarerenanc. (or la pananc., if you're using the Muslim calendar)

Created by rlpowell. Last Modification: Sunday 04 of September, 2005 05:47:19 GMT by rlpowell.