Daylight "disc" ? Over Negros Island, Philippines, by amateur astronomer working on Observatory dome

BACOLOD CITY (10-deg/50-min N-lat; 122-deg/51-min E-long;) Province of Occidental Negros PHILIPPINES  It was a clear sunny mid-afternoon day, and I was on our rooftop supervising the construction of the Observatory dome.  At the time, the other witness was doing the welding job on the dome while I was seated (on the roof)facing due east.
Then this "light" which I would estimate to be of magnitude (brightness) of about -2 or -3.0 (or about the brightness of Venus at the time of its greatest brilliancy or a little brighter), caught my attention. (But Venus could never be more than 48 degrees in angular distance from the sun during the times of its greatest elongation,so Venus is definitely ruled out as a possibility).
If my memory serves me right, I think I also called the attention of the welder/laborer to this bright object.
 It was moving too slow, but not slow enough compared to an aircraft (viewed flying from a far distance).  My initial comprehension was that it was an aircraft somehow reflecting the afternoon sun which was at my back, due west, at the time.
Looking at it, however, I could not discern any noticeable appendage(s)that would indicate its nature as an aircraft- and that the object simply appeared as a bright (starlike) object against the (blue of the) daytime sky. What caught my interest was the fact that the light (from my perspective and viewpoint) did not appear to be reflected sunlight in a way.
 It was about 40 degrees altitude when first seen, and its rather slow movement in the sky towards a northernly direction took it inside some cloud cover after which it was not seen again (though it was still visible through portions of cloud breaks).
A few seconds after it was first sighted, the intense (starlike) lighting seemed to have faded to a dull metallic (greyish) color, but I could still not discern any noticeable appendages or structures to indicate that it was an aircraft. From its apparent distance, no sound was heard (although no sound may be expected even from a passing aircraft at that distance which I have no way of estimating).
 It is common for me to watch a commercial airliner from Australia passing through the sky at about this time of the afternoon, but it was at a different date than its usual flight schedule.  Also, the commercial jet aircraft leaves contrails. That object did not. All these/ the sighting took no less than 2 minutes- but could not have been more than 3-minutes, in duration.
 It could not have been a balloon or blimp since we don't have (normally) these things flying around in a country like the Philippines.
As a non-professional (amateur) astronomer and formerly a Field Investigator for CUFOS, I am inclined to believe it may have been a mis-identified man-made aircraft of some kind, UNLESS it was indeed something OTHERWISE.
 P.S./ This Report was earlier submitted to CUFOS after the sighting incident. It is submitted here only for purposes of public information and official recording with your organization.