如何在 Javascript 中将 UTC/GMT 日期时间转换为 CST？ （不是本地的，CST 总是）

Question

I have a challenge where backend data is always stored in UTC time. Our front-end data is always presented in CST. I don't have access to this 'black box.'

I would like to mirror this in our data warehouse. Which is based in Europe (CET). So "local" conversion will not work.

I'm wondering the simplest, most straightforward way to accurately convert UTC time (I can have it in epoch milliseconds or a date format '2015-01-01 00:00:00') to Central Standard Time. (which is 5 or 6 hours behind based on Daylight Savings).

I see a lot of threads about converting to 'local' time... again I don't want this, nor do I simply want to subtract 6 hours which will be wrong half the year.

Anyone have any ideas? This seems to be a very common problem but I've been searching for a while, and have found nothing.

Answer 1

I have a challenge where backend data is always stored in UTC time. Our front-end data is always presented in CST. I don't have access to this 'black box.'

I would like to mirror this in our data warehouse. Which is based in Europe (CET). So "local" conversion will not work.

I'm wondering the simplest, most straightforward way to accurately convert UTC time (I can have it in epoch milliseconds or a date format '2015-01-01 00:00:00') to Central Standard Time. (which is 5 or 6 hours behind based on Daylight Savings).

I see a lot of threads about converting to 'local' time ... again I don't want this, nor do I simply want to subtract 6 hours which will be wrong half the year.

Anyone have any ideas? This seems to be a very common problem but I've been searching for a while, and have found nothing.

Answer 2

I have a challenge where backend data is always stored in UTC time. Our front-end data is always presented in CST. I don't have access to this 'black box.'

I would like to mirror this in our data warehouse. Which is based in Europe (CET). So "local" conversion will not work.

I'm wondering the simplest, most straightforward way to accurately convert UTC time (I can have it in epoch milliseconds or a date format '2015-01-01 00:00:00') to Central Standard Time. (which is 5 or 6 hours behind based on Daylight Savings).

I see a lot of threads about converting to 'local' time ... again I don't want this, nor do I simply want to subtract 6 hours which will be wrong half the year.

Anyone have any ideas? This seems to be a very common problem but I've been searching for a while, and have found nothing.

Answer 3

I have a challenge where backend data is always stored in UTC time. Our front-end data is always presented in CST. I don't have access to this 'black box.'

I would like to mirror this in our data warehouse. Which is based in Europe (CET). So "local" conversion will not work.

I'm wondering the simplest, most straightforward way to accurately convert UTC time (I can have it in epoch milliseconds or a date format '2015-01-01 00:00:00') to Central Standard Time. (which is 5 or 6 hours behind based on Daylight Savings).

I see a lot of threads about converting to 'local' time ... again I don't want this, nor do I simply want to subtract 6 hours which will be wrong half the year.

Anyone have any ideas? This seems to be a very common problem but I've been searching for a while, and have found nothing.

Answer 4

Maybe you can use something like the following. Note, that is just an example you might need to adjust it to your needs.

    let cstTime = new Date(createdAt).toLocaleString("es-MX", {
    timeZone: "America/Mexico_City" });

Answer 5

You can use below code snippet

 // Get time zone offset for CDT or CST const getCdtCstOffset = () => { const getNthSunday = (date, nth) => { date.setDate((7*(nth-1))+(8-date.getDay())); return date; } const isCdtTimezoneOffset = (today) => { console.log('Today: ', today); let dt = new Date(); var mar = new Date(dt.getFullYear(), 2, 1); mar = getNthSunday(mar, 2); console.log('CDT Start: ', mar); var nov = new Date(dt.getFullYear(), 10, 1, 23, 59, 59); nov = getNthSunday(nov, 1); console.log('CDT End: ', nov); return mar.getTime()< today.getTime() && nov.getTime()> today.getTime(); } var today = new Date()// current date if (isCdtTimezoneOffset(today)) { return -5 } else { return -6 } } let cstOrCdt = new Date(); cstOrCdt.setHours(cstOrCdt.getHours()+getCdtCstOffset()) console.log('CstOrCdt: ', cstOrCdt);

Answer 6

I have a challenge where backend data is always stored in UTC time. Our front-end data is always presented in CST. I don't have access to this 'black box.'

I would like to mirror this in our data warehouse. Which is based in Europe (CET). So "local" conversion will not work.

I'm wondering the simplest, most straightforward way to accurately convert UTC time (I can have it in epoch milliseconds or a date format '2015-01-01 00:00:00') to Central Standard Time. (which is 5 or 6 hours behind based on Daylight Savings).

I see a lot of threads about converting to 'local' time ... again I don't want this, nor do I simply want to subtract 6 hours which will be wrong half the year.

Anyone have any ideas? This seems to be a very common problem but I've been searching for a while, and have found nothing.