MIDI Song Position Pointer (0xF2): Bug or Feature?

When the song position is 1.1.1.0 the Song Position Pointer is 0.
When the song position is 1.1.1.1 the Song Position Pointer is 1.

Accoring to: Summary of MIDI 1.0 Messages
“This is an internal 14 bit register that holds the number of MIDI beats (1 beat= six MIDI clocks) since the start of the song. l is the LSB, m the MSB.”

How can it be one one tick after 1.1.1.0. After six Midi clocks, we are already at 1.1.2.0 and not at 1.1.1.1.

Is this a bug or a feature, or can the behaviour setup somewhere? I would expect that the song position pointer is increment at the end of a beat and not at the beginning.