I am building an iOS and blackberry app which needs to accurately capture the time of an event that occurs every 30-45 minutes in the background. I also need to correctly figure out the local time at which this event occurs so i can bucket the event by the correct day, after accounting for day light saving. i do not want to rely on device time to avoid the case in which the user has intentionally/unintentionally set the wrong time on the device.
(a) any suggestions on how i might be able to capture the accurate time when the event occurs? Should i be storing this in UTC or the local time (LT)? (b) if the time in (a) above is stored in UTC, then i have come across 3 services which i can use to convert from UTC to LT based on the lat-long of the event: (i) geonames.org, (ii) earthtools.org, (iii) askgeo.com. Any experience with the above/pros-cons? Any other recommendations? I found the piece on stackoverflow useful: http://stackoverflow.com/questions/41504/timezone-lookup-from-latitude-longitude
Thanks for the help N