On 7/30/2015 10:48, ISAAC J SCHWABACHER wrote:
Australia/Melbourne is a time zone, +1000 is an offset, and EST is an accident waiting to happen.
Australia/Melbourne is the *Olsan name* for a time zone. +1000 is the current legal definition of that timezone in terms of a GMT offset, EST is the common name of one of many timezones, likely US Eastern Standard Time, but could be one of many.
Timezones are political constructs that developers need to work around, not the other way around. Olsan's names are not written in law anywhere (that I know of).