| 2026-07-16 | Clock-setting std. |
| 2025-11-25 | Prime meridian hrs. |
| 2025-06-20 | Clock standard: Abbr. |
| 2024-07-10 | Clock-setting standard: Abbr. |
| 2023-02-19 | Big Ben hrs. |
| 2022-03-30 | Intl. standard used by many astrologers |
| 2021-07-06 | Hrs. at the prime meridian |
| 2020-08-10 | Setting at the prime meridian, for short |
| 2017-04-24 | Clock-setting std. |
| 2016-07-21 | Chronometric std. |
| 2014-09-06 | BBC World Service std. |
| 2014-07-01 | Clock-setting std. |
| 2014-05-05 | Clock-setting standard: Abbr. |
| 2014-03-30 | BBC std. |
| 2013-03-07 | Frequent abbr. in BBC announcements |
| 2013-01-27 | Intl. standard |
| 2012-04-14 | Zero-deg. setting |
| 2012-03-19 | World clock std. |
| 2011-07-22 | Setting for BBC reports, in brief |
| 2011-06-30 | Certain world std. |
| 2010-10-02 | Prime meridian hrs. |
| 2010-09-19 | See 63-Across |
| 2010-08-20 | Std. in chronometry |
| 2008-09-24 | Clock setting at 0 degrees longitude: Abbr. |
| 2008-05-19 | London hrs. |
| 2007-03-23 | Chronometric std. |
| 2006-04-05 | Intl. standard |
| 2005-07-10 | Frequent abbr. in BBC announcements |
| 2005-04-16 | Chronometric inits. |
| 2004-04-22 | You can set your watch by it: Abbr. |
| 2003-12-17 | Clock standard: Abbr. |
| 2003-05-03 | Zulu, in the military: Abbr. |
| 2002-11-01 | Clock std. |
| 2001-11-16 | Clock std. |
| 2001-04-27 | Clock standard: Abbr. |
| 1998-04-30 | Clock-setting std. |
| 1997-08-06 | All clocks are set by it: Abbr. |
| 1996-03-03 | Prime meridian std. |