grayling feeding times?

Are there certain periods of the day in winter when grayling are more active and more likely to feed?
I was out on the Anton from about 9ish but nothing was interested until 11 or so when it seemed there were more fish visible, and feeding.
It was very cold, bright, water was low and the light wind was Nwesterly!
Can't wait for May

I've found that Grayling feed at all times of day sub surface in winter, however if you're looking for a hatch most of these in winter occur towards the warmest time of the day 12-2. could be that if you want to fish dries then this is the best time.

just before and just after dark , especially in winter !