You really should ask Red Hat rather than pclos!
That said, I can guess what is happening here. You have two errors relating to Time Zone, local time and UTC which cancel out in the Summer so you see the correct time, but the hardware clock is an hour behind system time. When 01:59:59 comes round, NTC sets one of the clocks back an hour, but the hardware clock (must be set to UTC) doesn't change. An hour later the clock calculated from that reaches 01:59:59 and your system sets the time back again.
As you have NTP active, the second change should be corrected at the next NTP sync.
But it's really a matter for Red Hat.