Bus every 20-30 min
You don’t need to buy ticket from Ekkamai to Pattaya before. There are several bus companies, tickets are sold at different ticket offices. I usually buy at box office No. 28 (the cheapest tickets).
Enjoy your trip!

Unfortunately not. Last updated in 2017. But the schedule was stable for several years and I think it is 85-90% relevant.
Also you can check schedule here:

Yes, it is very comfortable and fast to get

Sorry, i don’t know, what is it – Klong Rang 304

Hello, Jason! I think, better for use Mochit New Van Terminal and look for minibus (van) to Mae Klong (Maeklong)

Hello, Jiri Vrana! I’m not sure exactly at 11 am you can find a bus to the pier on Koh Chang, but you can try. In any case you can be sure that there will be a bus to Trat city (center of the province). These buses are usually sent from Ekkamai in Bangkok every hour or even more often.
Buy a ticket for the nearest bus you can in the ticket office 24 at the Ekkamai bus station. The bus will take you either to the bus station in the city of Trat (it’s out of city), or this bus will stop on the road, from where there will be a closer distance to the ferry pier. In both cases, local passenger pick-ups will already be waiting for you. For 50-70 THB they will take you to the ferry pier. Enjoy your travel!

First ferry to Koh Chang from Ao Thammachart pier 06:30 (6:30 a.m.)
Last ferry in 19:30 (7 p.m.)

Hello, Karine!
To save your time on vacation, I recommend using the buses from the Ekkamai bus station, which will take you directly to the pier or to the island of Koh Chang (without visiting Trat).
You can find large buses at the bus station (ticket office #24) or take advantage of the popular service of transport in Asia. Here you can not only see the current schedule of routes, but also buy tickets online. On the route minibuses of TTT company operate, which quickly and inexpensively take you to the pier or to the island (there are combined tickets for minibus + ferry).

But if you need a night bus, then you also do not have to worry. In Thailand, the carriers work well and you do not have to wait long for the songthaew if you do not come to the pier, and to Trat city…

I would like to go to koh chang from bangkok, is it possible from the ekkamai bus terminal ?
And after that, do we have to take a song taew ? if so, when is the first departure of the song taew to the ferry ?

When is the first eparture of the ferry ?

Thank you in advance,
Best regards,

Karine

I would like to travel to Koh chang from bangkok, does ekkamai bus terminal has bus in the night ?
And once there, do we have to take song taew after the bus ? (if yes, when is the first song taew departure ?)

And when is the first ferry departure ?

Thank you in advance for you respond,
Kind Regards,

Karine

Hi David. I think it’s better not to use a bus, but an BTS Skytrain. It’s fast and convenient. Near the Ekkamai bus terminal there is the station BTS Ekkamai. You need to buy a ticket to the Phaya Thai station. This is 44 THB and trip is about 16 minutes (9 stations). At Paya Tai Station, you must change the metro line and get to the airport on the blue train City Line (45 THB and about 30 min). The station is located on the ground floor of Suvarnabhumi Airport. Those, the entire trip will cost just under 3 USD.
Also there are bus routes №501 and №545. But their cost is 100 baht and I did not use them and do not know the exact schedule, so I can not recommend. Have a nice trip!

You can find a bus, but not from the Ekkamai bus terminal, but from the Southern Bus Terminal. The cost is not more than 180-200 THB per person.
Unfortunately, you can not buy a ticket for such a late bus to Cha Am with the help of my favorite transport service in Asia. Only car transfer…
There are also minibuses from the Victory Monument in Bangkok, but I’m not sure there are routes to Cha-Am after 19-30

Здравствуйте, Ирина!
Для поездки в Канчанабури лучше использовать или два Южных автовокзала Sai Tai (старый и новый) или Северный автовокзал (Morchit terminal) (до него проще добраться). Можете увидеть расписание и цену тут:
https://farang.12go.asia/ru/travel/bangkok/kanchanaburi?date=2017-11-22

No. You need go to Southern Bus Terminal. You can read article about this big bus station on the website
http://thai-rest.com/southern-bus-terminal-in-bangkok-review-bus-timetable-and-fares/