NIST Radio Station WWVB concluded the test of a experimental advance notification system for daylight saving time (DST) on July 10, 2007. This testing began on June 21, 2007 and involved using bit 54 of the WWVB time code, which has previously been unused. The decision was made NOT to implement the new DST system because of possible adverse effects that it had on some existing radio controlled clocks.
During normal operation, the 60 kHz signal from WWVB is transmitted 24 hours per day, 7 days a week. The table includes periods since January 1, 2007 when the signal was off or intermittent for more than 5 minutes.
Date | MJD | Began (UTC) | Ended (UTC) |
---|---|---|---|
12-05-2007 | 54439 | 0336 | 0433 |
10-13-2007 | 54386 | 1928 | 2016 |
08-10-2007 | 54322 | 0600 | 0658 |
07-18-2007 | 54299 | 1658 | 2125 |
07-02-2007 | 54283 | 1654 | 1704 |
06-27-2007 | 54278 | 1550 | 1909 |
06-21-2007 | 54272 | 0326 | 0424 |
06-17-2007 | 54268 | 1048 | 1147 |
06-17-2007 | 54268 | ---- | 0055 |
06-16-2007 | 54267 | 2158 | ---- |
06-07-2007 | 54258 | 0816 | 0925 |
05-07-2007 | 54227 | 1535 | 2220 |
04-26-2007 | 54216 | 2237 | 2258 |
03-27-2007 | 54186 | 1355 | 1407 |
03-06-2007 | 54165 | 2251 | 2302 |
02-16-2007 | 54147 | 1302 | 1357 |
01-25-2007 | 54125 | 1138 | 1257 |