Open PS2 Loader don't care about the date and time. Try to remove your theme and try again to run OPL.
Another approach would be to cut out config from the OPL folder from your MC and let OPL start with default settings maybe the settings file got corrupted.
Check these possibilities and report back if it helped or not.
PS2 SCPH-70004 V12 PAL + HDCOMBO + 160 GB Samsung HDD + OPL 0.9.1
PS2 SCPH-70004a V13 PAL Satin Silver
2 x Official Sony 8mb card +FMCB 1.8c + uLE 4.42b
Datel Max Memory 32mb card +FMCB 1.8b + uLE 4.42
Memor32 + Memento FW 1.2e