Google hinted the Android 5.0 in its recent Twitter post while announcing a new Google Now utility and we can notice that the clock was at 5:00 when these screen shots were taken. Wondering how this is linked to the Android update? Google method while introducing its Android iterations here it is:
Earlier when Android 4.4 (KitKat) was released many screenshots were clocking the time at 4:40 and it was the same in the case of Ice Cream Sandwich. Google has following this trend of changing the time when ever there is a major release in its Android Operating System.