UO-22 was launched on 17 July 1991. It's now Non-Operational. I predict here that UO-22 might be passed over just 100000 of the orbit number using the latest TLE.
OSCAR 22 (UoSAT 5) 1 21575U 91050B 10212.53322685 .00000036 00000-0 25462-4 0 8963 2 21575 098.4959 161.9541 0006690 228.5705 131.4898 14.39726937999601
100000 - 99960 = 40 ... orbit numbers until 100000 40/14.39726937 = 2.778304619 ... orbits/mean motion = days 212.53322685 + 2.778304619 = 215.311531469 ... epock time
215 - 212 = 3 ... 3rd Aug 2010 0.311531469 * 24 = 7.476755256 ... 7 hours 0.476755256 * 60 = 28.60531536 ... 28 minutes 0.605315360 * 60 = 36.31892160 ... 36 seconds
Therefore it is 07:28:36 UTC, 3rd Aug 2010.
It maybe contains +/- one and a half hour's obserbational lag. In addition, the counter number returns to 0 when the orbit number exceeds 100000.
JE9PEL, Mineo Wakita