Confirmed. Happened to me: when time is set to 0, black dots appears in all the sky area and the sun texture "cuts" a part of the black (see the images).
I made a list with the affected shaders: fxaa, art, bumpy, blobs2, pencil, color_convolve, deconverge, flip, invert, scan_pincushion, bits, desaturate, green, blur, wobble, blobs, antialias, spider
The shaders notch, ntsc, outline, phosphor, sobel and creeper aren't affected.
Conor McS, can you confirm this works with the color_convolve shader in 14w21b? I have tried removing that section of the json file and I still experienced the black bar in the background. I tried modifying the json file via a resource pack and I also tried a custom jar file with the changed file. In both cases the black bar still existed.
my previous solution apparently does not work with all the shaders, i have since found a few more (spider, outline, and some others) which do not get fixed fully, as such i will not be helping anyone else who attempts to use my previous method, and will not be telling anyone else as it is a waste of time.
It does that for most of the shaders