Could it be Venus? It has been very bright in the night sky for months and the following entries found on the web refer to it being visible in daylight:
"Venus is actually not difficult to see in broad daylight with the unaided eye, if you know where to look. I found it readily from South London when I knew it to be close to the Moon before the occultation in December, but since then I have again found it several times just by viewing from my sofa through my south-facing lounge window. Focusing the eyes on the blue backdrop is part of the difficulty, another reason why it helps to have the more readily located Moon nearby, but once you find Venus's brilliant glint, it is obvious. The photo in my link shows that Venus actually shines brighter, area for area, than the Moon, but then Venus has dazzlingly reflective cloudtops and the Moon is made of relatively dark rock! "
"Venus is a "morning star" this month. Like Mercury, Venus undergoes dramatic changes during April, gaining half a magnitude in brightness, increasing in illumination from 2% to 24%, and decreasing in apparent size from 58.6 arc seconds to 39.9 arc seconds. It is occulted by a 17% illuminated crescent Moon on April 22. For information on this daylight occultation, see
http://www.lunar-occultations.com/iota/pleiades/pleiades.htm"
