Add language setting for time formatting.

src/General/Settings.coffee

@@ -493,7 +493,7 @@ Settings =
       $.id('lastarchivecheck').textContent = 'never'
 
     items = {}
-    for name in ['archiveLists', 'archiveAutoUpdate', 'captchaLanguage', 'boardnav', 'time', 'backlink', 'fileInfo', 'QR.personas', 'favicon', 'usercss', 'customCooldown', 'jsWhitelist']
+    for name in ['archiveLists', 'archiveAutoUpdate', 'captchaLanguage', 'boardnav', 'time', 'timeLocale', 'backlink', 'fileInfo', 'QR.personas', 'favicon', 'usercss', 'customCooldown', 'jsWhitelist']
       items[name] = Conf[name]
       input = inputs[name]
       event = if name in ['archiveLists', 'archiveAutoUpdate', 'QR.personas', 'favicon', 'usercss'] then 'change' else 'input'
@@ -646,6 +646,9 @@ Settings =
   time: ->
     @nextElementSibling.textContent = Time.format @value, new Date()
 
+  timeLocale: ->
+    Settings.time.call $('[name=time]', Settings.dialog)
+
   backlink: ->
     @nextElementSibling.textContent = @value.replace /%(?:id|%)/g, (x) -> ({'%id': '123456789', '%%': '%'})[x]
 

src/General/Settings/Advanced.html

@@ -64,6 +64,7 @@
   <div>Minute: <code>%M</code></div>
   <div>Second: <code>%S</code></div>
   <div>Literal <code>%</code>: <code>%%</code></div>
+  <div><a href="https://www.w3.org/International/articles/language-tags/" target="_blank">Language tag</a>: <input name="timeLocale" class="field" spellcheck="false"></div>
 </fieldset>
 
 <fieldset>

src/Miscellaneous/Time.coffee

@@ -41,13 +41,26 @@ Time =
     'December'
   ]
 
+  localeFormat: (date, options, defaultValue) ->
+    if Conf['timeLocale']
+      try
+        return Intl.DateTimeFormat(Conf['timeLocale'], options).format(date)
+    defaultValue
+
+  localeFormatPart: (date, options, part, defaultValue) ->
+    if Conf['timeLocale']
+      try
+        parts = Intl.DateTimeFormat(Conf['timeLocale'], options).formatToParts(date)
+        return parts.map((x) -> if x.type is part then x.value else '').join('')
+    defaultValue
+
   zeroPad: (n) -> if n < 10 then "0#{n}" else n
 
   formatters:
-    a: -> Time.day[@getDay()][...3]
+    a: -> Time.localeFormat @, {weekday: 'short'}, Time.day[@getDay()][...3]
-    A: -> Time.day[@getDay()]
+    A: -> Time.localeFormat @, {weekday: 'long'},  Time.day[@getDay()]
-    b: -> Time.month[@getMonth()][...3]
+    b: -> Time.localeFormat @, {month:   'short'}, Time.month[@getMonth()][...3]
-    B: -> Time.month[@getMonth()]
+    B: -> Time.localeFormat @, {month:   'long'},  Time.month[@getMonth()]
     d: -> Time.zeroPad @getDate()
     e: -> @getDate()
     H: -> Time.zeroPad @getHours()
@@ -56,8 +69,8 @@ Time =
     l: -> @getHours() % 12 or 12
     m: -> Time.zeroPad @getMonth() + 1
     M: -> Time.zeroPad @getMinutes()
-    p: -> if @getHours() < 12 then 'AM' else 'PM'
+    p: -> Time.localeFormatPart @, {hour: 'numeric', hour12: true}, 'dayperiod', (if @getHours() < 12 then 'AM' else 'PM')
-    P: -> if @getHours() < 12 then 'am' else 'pm'
+    P: -> Time.formatters.p.call(@).toLowerCase()
     S: -> Time.zeroPad @getSeconds()
     y: -> @getFullYear().toString()[2..]
     Y: -> @getFullYear()

src/config/Config.coffee

@@ -857,6 +857,7 @@ Config =
   captchaLanguage: ''
 
   time: '%m/%d/%y(%a)%H:%M:%S'
+  timeLocale: ''
 
   backlink: '>>%id'