Just wait until you have to do this under government controlled (tariff) environments. Years ago I worked on a tele-conference platform for large international telecom. We built the software to run all aspects of their platform including billing.
Government tariffs covered billing rules for each leg of a call including rates based on caller's local time of day. Converting bridge time to local time via area/country codes(only data available) and time-zones is quite a mess. Add DST calculations to that per locale to reconcile negative duration legs or legs that should be 1.5 hours but show up as .5 hours just makes it cloudier.
If your system repeatedly gets it wrong, you could be in trouble for billing fraud or tariff violation. No joy in that job.
Government tariffs covered billing rules for each leg of a call including rates based on caller's local time of day. Converting bridge time to local time via area/country codes(only data available) and time-zones is quite a mess. Add DST calculations to that per locale to reconcile negative duration legs or legs that should be 1.5 hours but show up as .5 hours just makes it cloudier.
If your system repeatedly gets it wrong, you could be in trouble for billing fraud or tariff violation. No joy in that job.