Question

我正在处理的应用程序已作为目标用户USA。而且（你可能知道）在美国有不止一个时区。所以我有些疑惑：

那么我如何才能获得服务器端的当前时间当前用户？
我如何存储DateTime数据以显示正确的时间每个用户？
我如何比较时间（例如：user.event.created > datetime.now()）？ .now()将使用哪个时区？
我应该在settings.py文件中设置什么TIME_ZONE。

这是一个API，通过JS获取用户的时区不是一个选项。我通过TokenAuthentication获得当前用户。

Answer 1

对UTC使用settings.py并从Javascript中获取他们的时区偏移量：

var utcOffset = -((new Date()).getTimezoneOffset()) / 60;

e.g。现在洛杉矶utcOffset == -7

不幸的是，这不会考虑以后的夏令时更改（偏移更改为-8），因此您可能必须在检索时将其弄清楚才能获得Pacific/Los_Angeles。否则，您可以随时以注册形式询问用户是否对您的业务非常重要。

编辑：由于您使用的是API，因此您还可以尝试使用IPInfoDB API根据客户端IP地址进行地理定位。它并不总是完全准确，但几乎总是足以获得正确的时区。

Answer 2

不要使用datetime.now（），而是使用timezone模块中的now（）函数。

from django.utils import timezone

now = timezone.now()

Django将确定您所在的时区并相应地进行比较。

user.event.created > timezone.now()

https://docs.djangoproject.com/en/1.8/topics/i18n/timezones/

Answer 3

解决方案是始终将unix时间戳存储在数据库中。您可以使用time.time()生成。这意味着您的模型应该有一个Floatfield（甚至BigIntegerField，具体取决于所需的准确性）。

您的模板应按原样显示数值。然后你需要一点点javascript来将unix时间戳转换为日期时间。

new Date(unix_timestamp);

Answer 4

您的Web应用程序的用户可能处于不同的时区，因此有必要转换为适当的时区。您可以创建一个中间件并使用activate函数来设置适当的时区。您可以通过在目标网页中对 Free IP Geolocation API 进行ajax api调用来获取客户端时区，时区值可以保存在cookie变量中，以后可以在中间件中进行访问

landingpage.html

create-link-with one-of potentialHomes [  set color red

middleware.py

undirected-link-breed [own-links own-link]
undirected-link-breed [rent-links rent-link]
breed [city-centers city-center]
breed [households household]
households-own 
[ 
  age 
  money 
  income 
  monthly-income 
  consumption 
  monthly-consumption 
  hh-size race 
  preference 
  net-income
  net-monthly-income
  myHouse
]
breed [houses house]
houses-own 
[ 
  cost 
  down-payment 
  mortgage-payment 
  rent 
  rent-premium 
  rooms 
  onMarket
  owner-occupied
  rental
  onMarket?
]
patches-own [ 
  seed?  ;;district seed
  district  ;;district number
  full? ;;is the district at capacity?
  quadrant 
]

to setup
  clear-all
  reset-ticks
  setup-patches
  set-default-shape households "person"
  create-households num-households [ setxy random-xcor random-ycor ]
  set-default-shape houses "house"
  create-houses num-houses [ setxy random-xcor random-ycor ]
  setup-households
  setup-houses
  setup-market
  generate-cities
end

to generate-cities
  let center-x random-xcor / 1.5 ;;keep cities away from edges
  let center-y random-ycor / 1.5
end

to setup-patches
  ask patches with [pxcor > 0 and pycor > 0] [set quadrant 1 set pcolor 19 ]
  ask patches with [pxcor > 0 and pycor < 0] [set quadrant 2 set pcolor 49 ]
  ask patches with [pxcor < 0 and pycor < 0] [set quadrant 3 set pcolor 139 ]
  ask patches with [pxcor < 0 and pycor > 0] [set quadrant 4 set pcolor 89 ]
end

to setup-households
  ask households
    [ set age random-poisson 38
      set money random-exponential 30600
      set income random-exponential 64324
      set monthly-income income / 12
      set consumption .5 * income
      set monthly-consumption consumption / 12 
      set hh-size random 6 + 1
      set net-income income - consumption
      set net-monthly-income monthly-income - monthly-consumption
    ]
end

to setup-houses
  ask houses
    [ set cost random-normal 300000 50000
      set down-payment cost * down-payment-rate
      set mortgage-payment (cost - down-payment) / 360 
      set rooms random-exponential 3
      set onMarket 1
      set rent mortgage-payment + mortgage-payment * .25
      set owner-occupied 0
      set rental 0
    ]
end

to setup-market
  ask houses
    [ set onMarket? TRUE ]
  ask households 
    [ ifelse any? houses with [ [money] of myself > down-payment and [net-monthly-income] of myself > mortgage-payment ]
      [ let potentialHomes houses with [[money] of myself > cost and onMarket? ] 
        create-link-with one-of potentialHomes [ 
          set color red
        ]
      ] 
      [ 
        ifelse any? houses with [ [net-monthly-income] of myself > rent]
[ let potentialRentals houses with [ [net-monthly-income] of myself > rent and onMarket? ] 
  create-link-with one-of potentialRentals [ set color blue ]
]
[ die ]
      ]
  ]
  ask houses 
    [ if any? link-neighbors [set onMarket FALSE ] 
      ;if any? link-neighbors and color red [ set owner-occupied 1 ]
      ;if any? link-neighbors and color blue [ set rental 1 ]
  ]
end

to go
  move-households
  tick
end

to move-households
  ask households [
    move-to myHouse
  ]
end

settings.py

<script>
$.ajax({
        url: 'https://freegeoip.app/json/',
        dataType: 'json',
        success: function (data) {
            document.cookie = 'timezone=' + data['time_zone'] + '; path=/';
        }
      });
</script>

]

在Django中使用多个时区

4 个答案: