Question

My web server is in east coast.
I sent an email from my web server at 1PM PST time which is 4PM Eastern time.
I am resided in west coast and when I see the page, it shows 4PM which is future time for me.

How can I see 1PM, someone in east coast 4PM and so on?

The date is stored in MongoDB which is UTC. I also convert date before displaying:

@Model.DateSent.ToLocalTime().ToString();

This is how I set the time when mail is sent:

DateTime.UtcNow <-- So I am storing date in UTC already

Thanks

Answer 1

There are two parts to your question. The first is the mechanics of localizing a dateTime in C#. Since I’m not a Windows guy, I’ll leave that to either someone else to answer or you to look up in the docs, but I’m willing to bet that ToLocalTime() has a friend that takes a TimeZone or a Locale.

The second part, which is more interesting, and something I’ve had to deal with a few times in the past is how to know what timezone to use. There’s no right answer, but there are a few strategies:

• The simplest, and perhaps the best, if there’s a concept in your system of a user account
  is to simply make the Locale a user preference.
• If there’s no concept of a user account one’s always logged into there are a few ways
  to go
  • you could make it a choice that is saved in the session, but that’s a bit annoying
    to force them to select every time
  • a better alternative might to be geocode the inbound IP address and set it from
    that. There are geocoding apps, databases and services. Most cost, but I know
    MaxMind has a free edition that does ok. That will mostly work. The catch is
    users coming via some large private network. I live near Philadelphia. My home
    network usually geocodes pretty well, though a few services place me in Delaware,
    where my ISP is located. But at work, where the whole company goes out through
    a single web proxy, I look like I’m in North Dakota.
  • more reliable, but perhaps more involved, is to grab the browser’s timezone
    using getTimezoneOffset() in Javascript and push the answer up to the server.
• I suppose the other option might be to convert the time locally in the browser,
  where the timezone is freely availiable, but that implies that the data is
  coming down via AJax or similar and then being updated via JavaScript. Fine if
  you’re doing a app that is fundimentally Ajax RIA based, just send the data
  in UTC or as a time_t. But kind of silly and annoying for a classic web app
  that isn’t already processing all the data client side.

My first choice would be a user preference. If that’s not an option I’d probaly push the timezone from the client. And if that’s too involved, go for IP geolocation.