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<DIV>Hello,</DIV>
<DIV> </DIV>
<DIV>I'm investigating how to deal with timezones for an application that will
get to</DIV>
<DIV>processes billions of timestamped events, generated in just about any part
of the world.</DIV>
<DIV>Timestamps are in local time (without timezone, only post- and other codes)
and we need </DIV>
<DIV>them in UTC time. Money is involved, so it is of critical importance
that intervals </DIV>
<DIV>between events are calculated correctly.</DIV>
<DIV> </DIV>
<DIV>There's two steps involved in this:</DIV>
<DIV> </DIV>
<DIV>- given some geo data and some lookup tables from a database like
geopostcodes.com, determine the timezone id</DIV>
<DIV>- convert to UTC using the latest Time Zone Database</DIV>
<DIV> </DIV>
<DIV>Development wise it's fairly simple to automate. We're using joda
time and this library allows to </DIV>
<DIV>plugin a custom Timezone provider which can then use the latest TZ
database.</DIV>
<DIV> </DIV>
<DIV>However, I see some issues:</DIV>
<DIV> </DIV>
<DIV>1) I noticed that certain timezone ids are deleted in newer versions:
tzdata2014a contains </DIV>
<DIV>America/Shiprock, newer versions don't. This may lead to issues
whenever recalculations are needed </DIV>
<DIV>in the future. What is the likelyhood that ids are deleted?</DIV>
<DIV> </DIV>
<DIV>2) Do rules from the past ever change? In other words, can we assume
that a recalculation of a past </DIV>
<DIV>local date to a UTC date will always yield the same result with newer
versions of the TZ database? </DIV>
<DIV>If so, is this a common thing and would one then recommend saving the TZ
database version with </DIV>
<DIV>which the conversion was performed along with the UTC date?</DIV>
<DIV> </DIV>
<DIV>Hope one of you can shed some light!</DIV>
<DIV>Cheers,</DIV>
<DIV>Joris</DIV></DIV></DIV></BODY></HTML>