allow cron to record user's current timezone offset in preferences.timezoneOffsetAtLastCron (initial stage of cron timezone fix for https://github.com/HabitRPG/habitrpg/issues/3806 )

common/script/fns/cron.js

@@ -36,6 +36,9 @@ module.exports = function(user, options) {
   }
   user.auth.timestamps.loggedin = new Date();
   user.lastCron = now;
+  if (_.isFinite(+user.preferences.timezoneOffset)) {
+    user.preferences.timezoneOffsetAtLastCron = user.preferences.timezoneOffset;
+  }
   if (user.items.lastDrop.count > 0) {
     user.items.lastDrop.count = 0;
   }

test/common/algos.mocha.js

@@ -53,6 +53,7 @@ let beforeAfter = (options = {}) => {
     before.preferences.dayStart = after.preferences.dayStart = options.dayStart;
   }
   before.preferences.timezoneOffset = after.preferences.timezoneOffset = options.timezoneOffset || moment().zone();
+  before.preferences.timezoneOffsetAtLastCron = after.preferences.timezoneOffsetAtLastCron = before.preferences.timezoneOffset;
   if (options.limitOne) {
     before[`${options.limitOne}s`] = [before[`${options.limitOne}s`][0]];
     after[`${options.limitOne}s`] = [after[`${options.limitOne}s`][0]];

website/src/models/user.js

@@ -350,6 +350,7 @@ var UserSchema = new Schema({
     skin: {type:String, 'default':'915533'},
     shirt: {type: String, 'default': 'blue'},
     timezoneOffset: Number,
+    timezoneOffsetAtLastCron: Number,
     sound: {type:String, 'default':'off', enum: ['off', 'danielTheBard', 'gokulTheme', 'luneFoxTheme', 'wattsTheme']},
     language: String,
     automaticAllocation: Boolean,