Işe saat dokuze yermi kala çıkacağim. I am leaving for work at 7.40.

thank you

" İşe saat dokuza yirmi kala çıkacağım = I am leaving for work at 8.40

 "İşe saat sekize yirmi kala çıkacağım =  I am leaving for work at 7.40

"Işe saat dokuze yermi kala çıkacağim. I am leaving for work at 7.40."

İşe saat sekize yirmi kala gideceğim. or

İşe gitmek için saat sekize yirmi kala evden çıkacağım. (işe gitmek için = in order to go to work) ev=home evden=from home

if we rewrite these sentences for present then;

gideceğim----> giderim/gidiyorum, çıkacağım----> çıkarım/çıkıyorum

If you use the future tense here, it means you will do this one time. but if you use the present or continues, we understand that you always go to work at this hour.

could you explain the kala çıkıyorum part please

 It is an idiom. "Sekize yirmi kala çıkıyorum" meaning is "i´m leaving/departing twenty to eight."

The ´kala´ part is from the word used to say ´at´ when saying the time is at xxx to yyy (I guess from kalmak, to remain, to stay.

Here is a short piece about saying ´at´ a certain time.

To say ´at´ a certain time such as ´at half 8´, these are the formulas.

The formula for ´at...past...´ is;

hour + -(y)i + minute +geçe

examples
altı on geçe = at 10 past 6
ikiyi çeyrek geçe = at quarter past 2

The formula for ´at....to...´ is;

hour +-(y)a/e +minute + kala

examples
dokuza beş kala = at 5 to 9
sekize çeyrek kala = at quarter to 8

at 8 o´clock = (saat) sekizde
at half past 4 = (saat) dört buçukta

 Doesnt have to be "işten çıkacağım ?

 İşten çıkacağım is I will leave work

 Aha ok.

"kala"s equivelant in English can be "to" but not "at". "at"s equivalent is "-de,-da"

Sekize on kala işe gideceğim.

I will go to work at ten to eight.

There is no equivalent of "at" in the Turkish sentence. Because there is no need to use it.

Sekizde işe gideceğim.

I will go to work at eight.

As you can see in the Turkish sentence there is "-de" which is the equivalent of "at" Because it is necessary to use it.

 You are wrong Gokk

İn "Sekize on kala..."  "kala" means "at" and that "to" you mentioned is final -e  from "sekize"

Nope. We use "kala" with "-e" suffix like "word + e + word + kala" You can translate "e kala" as "to" if you are saying the time. Actually "kala" comes from "kalmak"(to remain) and if you want to do a literal translation you shoud write "at ten remains eight" 

I know that " -e kala" are together but the the books point "kala" being the sign that is "at" some time. We are learning like this . Of course we dont use "kala" for other than time.

Like we see in dictionary:

-e/ -a kala = at....to...

I understand. But "kala" comes from "kalmak" and it is only logical when we translate it as "to". As you can see it is not a literal translation. But it is a mistake to think "kala" is equivalent to "at". 

Like we see in dictionary:

-e/ -a kala = at....to...

The problem here is we dont use a Turkish equivalent of "at" when we use "kala" or "geçe" in the sentence. But English speakers somtimes use "at" when they use "pass" or "to". So in dictionaries they use "at" and "to" together when translating -e/ kala. But look at the dictionary and you will see "at" is equivalent to "-de,-da" in Turkish. Translation here is not literal.

I understand. But in all books that teach turkish for foregners is explained like this. No matter from where "kala" comes for it matters what points. And it points "at". And, like we all know, "-e" points "to".

BTW in your profile you wrote that you hate grammar

Yes I hate grammer. But I know what -e/ kala means. It can be translated as "in the period of  x time remains to y time" İnstead of translating this way they translate it as "at...to"

 Gokuyum is right here Zeytinne.. "kala" is "to"..there are some mistakes we come across in turkish grammer books which claim to teach turkish to foreigners.

  Ok. You hate grammar r and you pretend to teach Turkish better than Turkish books are doing. Thats a high selfesteem .

What you dont want to understand is it is not the literal translation of the Turkish adverb that you see in the books but this doesn´t mean the books are wrong. There is a saying: "Translation is like a woman; beautiful one is not loyal; loyal one is not beautiful." As you can see when we translate it literally it doesnt sound beautiful in English. If we want it to be beautiful we must bear its disloyalty to itself.

-e kala and -i geçe points that its about "at"

Thats for us to understand its not about " var" or "geçiyor".

It is exactly the opposite. Let me correct it for you.

-e kala and -i geçe points that its about " var" or "geçiyor".

Thats for us to understand its not about "at"

Good luck at teaching Turkish! You need it ! 

Thanks for your good wishes.