I noticed that UO-22 might be passed over just 100000 of the orbit number before long. UO-22 was launched on 17 July 1991. It's now Non-Operational.
UO-22 1 21575U 91050B 10148.66466669 -.00000020 00000-0 77105-5 0 8445 2 21575 98.4922 98.6195 0008358 67.4032 292.8038 14.39719412990416
The above kep is 'NORAD TLE Sets Current Data'. The orbit number is 99041, so 959 to 100000.
100000 - 99041 = 959 ... orbit numbers until 100000 959/14.39719412 = 66.61020140 ... orbits/mean motion = days 148.66466669 + 66.61020140 = 215.27486809 ... epock time
The epock time 215.27486809 is 06:35:48 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