diff options
| -rw-r--r-- | www/js/utils.js | 26 |
1 files changed, 24 insertions, 2 deletions
diff --git a/www/js/utils.js b/www/js/utils.js index b8bbd76..eec81b0 100644 --- a/www/js/utils.js +++ b/www/js/utils.js @@ -74,10 +74,32 @@ function msToTimeString(time) { return h + ':' + m.pad(2) + ':' + s.pad(2) + '.' + hs; } +function get_rd_week(msEpoch) { + // + // This computes the current Rivendell Week based on the number + // of weeks since epoch. + // + // Explanation: + // epoch was at 01.01.1970 which was a Thursday. + // Monday in that week is (s-from-epoch + 3*24*60*60) seconds ago. + // This needs to be adjusted by the timezone offset for Europe/Vienna + // which is of course not constant (damn you daylight savings time) + // Divide this by (7*24*60*60) and you get the number of + // weeks since the Monday in the week of epoch adjusted for timezone offsets. + // This week had week number 3 so add an offset of 2 and + // get the modulo of 4. This rounded down gives you the current week + // with 0 meaning Week 1. So add 1 to that number and you will get + // the current RD week. + // + var sEpoch = ((+msEpoch) / 1000) ; + var week = Math.floor((((sEpoch + 259200)/604800) + 2) % 4) + 1; + return week; +} + function Clock(draw_callback) { this.draw_callback = draw_callback; - this.last_message = { t1: 0, t2: 0, t3: 0, t4: 0, tz_offset: 3600, week: 3 }; + this.last_message = { t1: 0, t2: 0, t3: 0, t4: 0, tz_offset: 3600 }; this.clock_offset = 0; this.clock_rtt = 0; @@ -92,7 +114,7 @@ function Clock(draw_callback) { time_str += (rdtime.getUTCMinutes() > 9 ? ':' : ':0') + rdtime.getUTCMinutes(); time_str += (rdtime.getUTCSeconds() > 9 ? ':' : ':0') + rdtime.getUTCSeconds(); - this.draw_callback(date_str, time_str, this.last_message.week); + this.draw_callback(date_str, time_str, get_rd_week(rdtime_ms)); } this.ntp_update = function(event) { |