I'm not sure that I agree with this. I'm not saying that you're wrong; you seem knowledgable, but I may not understand what you're trying to say. GMT does not change for daylight savings. In the UK, where GMT is the official time, they only use it during winter. During summer, they use British Summer Time (BST), which is GMT+1.alixaxel wrote:this forum (phpBB) for instance has an bug where it says that "All times are UTC [ DST ]", instead it should read "All times are GMT [ DST ]" because UTC is DST agnostic. GMT on the other hand has it's correspondent DST timezone (GST or BST I believe) which is UTC-1.
Everyone else in the world uses UTC as the official time reference, not GMT. So for our purposes, we can consider GMT to be a timezone that is UTC+0.
You're mixing GMT with UTC which causes confusion. In the context of this thread, when we talk about GMT we are using it as a time reference. GMT should no longer be used in this way because it was replaced by UTC. In other words, forget about GMT and use UTC instead.kaisellgren wrote:My friend from NYC is GMT-5 and I am GMT+2 so I am 7 hours ahead of his time, but now, however, he went to summer time so is he UTC-4 while I am UTC+2? Or in other words, is he GMT-5+DST and I am GMT+2 (no DST)?
Your friend's time is GMT-5 and yours is GMT+2. When he switches to daylight savings he is GMT-4. Using UTC is no different. He is on UTC-5 and you are on UTC+2. When he switches to daylight savings he is on UTC-4. I look at GMT and UTC as two different units of measurement, which happen to be equal to one another.
This I agree with, and I proposed a simple way of doing this with MySQL's TIMESTAMP columns in my first post in this thread.alixaxel wrote:the best way to deal with dates is to always grab the date and on the local user timezone and convert/store it in UTC, then you can convert it again to the timezone your user prefers.