The timestamp argument to pn_transport_tick is a pn_timestamp_t. pn_timestamp_t implies real time (wall clock) in that it's expressed as a time value based on epoch.
As seen in
QPID-6698, using a real time value for that argument can lead to problems if the real time is adjusted (eg. timezone, daylight savings, drift).
Instead, pn_transport_tick should be passed a monotonic clock source - one that does not reflect changes in real time.
All documentation and examples should be updated accordingly.