Time Zone Database Has New Home After Lawsuit
networkBoy writes "ICANN has taken stewardship of the time zone database after its original operators were sued for copyright infringement by an astrology software company, saying they will 'deal with any legal matters as they arise'. From the article: 'Without this database and others like it, computers would display Greenwich Mean Time, or the time in London when it isn't on summer time. People would have to manually calculate local time when they schedule meetings or book flights.'"
and no, the answer is not exactly 20 year ago (ignoring leap years) because timezone changes means that not all days are 24 hours
Time zones have nothing to do with how long a day is. Every time zone has 24 hour days. Unless you live in some weird alternate universe where some days are longer than others...
The changes in daylight savings time may impact exactly what time it is now but the only thing you have to deal with is whether you're currently in daylight savings time. Because within a year, switching to DST and back cancels itself out. A given year will have one day that acts like a 23 hour day and another that acts like a 25 hour day.
The only real thing that would make 20*365*24*60*60 (ignoring leap years) not exactly 20 years ago is if the standard for daylight savings time had changed between then and now. If daylight savings time was in effect then but not now (or not then but in effect now), you'd only be off by one hour.