[bwooce]

the only bit I'd prefer clarification on is:

Timestamp with Timezone

There’s seldom a case you shouldn’t be using these.

For recording most event times that's true but:

Birthdates (which can include times) shouldn't use them.

Calendaring should think very carefully too, should the 9am meeting move to 10am due to DST? or should it "stay put" but potentially move for other timezones?

[craigkerstiens]

Definitely some great points and valid cases. In the calendaring case I actually may enjoy the shift, but that would probably be a surprise to most. Will work to add these examples where you wouldn't want the with timezone behavior in.

[ragsagar]

Birthdates (which can include times) shouldn't use them.

I don't understand why you don't want to use timezone with birthdates(with time). Can you explain this, please?

[exogen]

I think because the common usage of birthdates doesn't take the timezone into account. e.g. if you were born on January 1st 9pm PST, that's January 2nd 12am EST – but your birthday is still considered January 1st no matter where you are in the world. So trying to correct such dates for timezones will show users their incorrect birthdate.

[NoMoreNicksLeft]

Birthdates are particularly difficult to handle properly in a database if there is even a slight chance that you'll need to enter a foreign immigrant into the data.

Just for instance, older Iraqis (if I remember correctly) tend to be part of a culture where their individual birthdates were never recorded, and each person was considered 1 year older on some September date (maybe even talking the Islamic calendar there too). Should you store that date in your database, pretending that it means the same thing as an American who knows they were born at 7:08pm EST on July 17th, 1977?

And that's just one example of many.

I think I learned about this one because intelligence officials were freaking out when they eventually noticed all these people sharing a "birthdate", and it made the news.

Data about human beings is highly un-normalizable, as evidenced by everyone trying to stuff anthroponyms into the American "first name, middle name, last name" paradigm.

[julie1]

http://www.postgresql.org/docs/9.1/static/datatype-datetime....

The postgresql manpage says it loud: don't fucking use timestamp with timezone. It is bounded to political decision that makes it unusable compared to an UTC TS. Plus good practices says: store UTC present in local

Does any one Read The Fantastics Manual these days?

[joevandyk]

The docs say "don't use time with time zone".

That's very different than timestamp with time zone, which you should be using unless you have a very good reason to not.