By default, if you’re using real-time and gradual (which generally you should be anyway), then 10 seconds. Just look for the interval(s) parameter in each layer and adjust to however many seconds you want the transition to happen over.
Ok when I’m use real time and gradual I get smooth transition on switch, but then SetTime is working strange. is now controlling time or SetTime can be still used?
Set the down-scale factor settings to 1 in the details-panel. That fixed it to me.
Try setting the date in the sky layer for all sequences to today’s date (or thereabouts) and seeing if that helps.
I just want to point out that his clouds WERE set to 1. Look at his first screenshot. The shadows have a visible blocky aesthetic.
Ah, also try to create a whole new sequense, if you already havent tried that. That can fix it sometimes too 
I have done that and both sequences have today date. But when I’m switch sequences then I get strange sun movement. Time of day going all over the place.
To be sure on my side I have created one sequences with sunny day (current day set for time and i have used real time and gradual transition). Then I have duplicated sequence and only changed Haze to high to get foggy day.
After that in real time I switch those two sequences and transition doesn’t work. When I switch it sun is moving and it looks like that two sequences are not synced in time. Shadow of the trees are moving back fort. Its look like that is ignoring my call to SetTime macro that I’m calling every frame. He is doing something but I don’t know what. It’s hard to even find pattern what is going on.
Did anyone achieved smooth transition between sequences and how?
I think if you make sure the first keyframe on the sequence you’re switching to is after the last keyframe being used in the first sequence, then it should be fine. The time of day won’t be smooth if you’re using real time and for example, doing something like :
Sequence 1, keyframe 1 at time 0.3 -> sequence 1, keyframe 2 at time 0.5 -> switch to sequence 2, with first keyframe at 0.3. On the sequence switch, the time and sun direction will reverse to go from 0.5 to 0.3.
My guessing is that when you switch sequence, goes to the first keyframe of the new sequence, and then gradually sets the new time (so yeah, the sun will move from the original position to the new one).
About the suggestion from @ . If I understand it correctly, let’s think I have 5 keyframes in Sequence1, and then I have only 1 keyframe in Sequence2, which is at 15:00. means that to switch correctly I should only change from Sequence1 to Sequence2 at 15:00 (so the original sun position of Sequence2 is the same as the current of Sequence1), right?
I think you could switch before 15.00, as it will interpolate between them, but you’d have to experiment with whatever other settings you’re using to see how smooth is. But certainly the point you switch at should be no later than 15.00 in example.
Yes but I have duplicated sequence so there is no difference between them (in order or key frames and duration) except one float parameter in one of the key frames. I have oly changes fog parameter in one of the sequencers and transition doesnt work.
What about your sky keyframes? If you have multiple sky keyframes then it’s going to move back to the first on the second sequence, when you switch. might explain strange sun movement.
@
Well, thank you a lot for your support! Sadly might not be exactly what we need for our project, as our weather system is too much dynamic for at the moment, but I would like to know if there are any plans on the roadmap to allow deeper changes of the sequences in real time. Thanks again!
4.12.5 compatible binary installer , when?
I bet has been asked before but cannot seem to find a good answer. Since clouds are volumetric what type of cost/expense that put on a game. What do people using the system usually see in FPS drop in using the system based on what GPU you are using?
C
If your game is 1920x1080 resolution, at typical settings, you should be seeing sky render at under 2ms on a GTX980-class card, under 4ms on an old GTX 760. Higher downscale settings will reduce the render time, so you can adjust it to meet your framerate needs. Remember there’s 16ms in a 60Hz frame, 10ms for 100fps.
To measure the render time, you can use “Get Profiling Text” in Blueprint:
&stc=1
outputs the timings in milliseconds: increase the GPU or CPU levels to get more detail about what’s taking the time up.
Probably next week, unless they release 4.12.6 by then. But the 4.12.4 installer should work with 4.12.5.
Editor works fine with 4.12.4 version but packaged project is pitch black.
Edit: nevermind, i forgot to copy dll’s from engine directory
Would be fantastic if something could be implemented to help with . Just writing to show that there is a demand for it. 
Do you have any ETA on when it might be implemented?
Does work in Linux? I crosscompiled for Linux using Epic’s instructions and it complained about the plugin.