如何通过java脚本查找系统区域时区名称

Question

Hi i have a typical requirement in my web application, i have to fill a dropdown box with all system timezones and set the selected time zone where from the client is browsing.

Only timezoneoffset is not enough to handle this suituation, since there are two reasons 1.the latest OS having more than one time zone with the same offset 2.If Day light save is enabled or disable(can be detected from Javascript) the offset will vary.

is ther any ways of handling this in Java script?

Answer 1

Short answer : Use this open source JavaScript project: jsTimezoneDetect . It is based on the code that MK linked here, which is great, but not enough since different regions within the same timezone start their daylight savings at different times. Hemisphere also plays a factor.

Long answer : One example is the -07:00 UTC timezone which basically has three sub timezones.

• US Mountain Standard Time (no daylight saving... this is Arizona)
• US Mountain Time (with daylight savings)
• Mexico Mountain Time (with daylight savings)

Assuming that you know your user's UTC offset you will now have to check whether your timezone uses daylight savings. Create one January and one June date and check these two dates. If their UTC offsets differ, then you are in a timezone that uses daylight savings.

Say that you have determined that your user is -07:00 with daylight savings, that means either US Mountain Time (America/Denver) or Mexico Mountain Time (America/Chihuahua). How to tell them apart? Well, the date they start their daylight savings differ.

US daylight savings starts in 2011 starts 13 March, and in Mexico it 4th April. So start with Denver and check if 13 march is summer time, no? Ok, check if 4th April is summer time. Yes? Bingo.

Answer 2

检查： 使用JavaScript自动检测时区 。