| E | O (JD) | O (dat) | Period |
| -3 | 2438300 | 1963-09-27 | 439.1 |
| -2 | 2438820 | 1965-02-28 | 436.45 |
| -1 | 2439238 | 1966-04-22 | 435.63 |
| 0 | 2439643 | 1967-06-01 | 434.94 |
| 1 | 2440080 | 1968-08-11 | 434.31 |
| 3 | 2440975 | 1971-01-23 | 434.23 |
| 4 | 2441384 | 1972-03-07 | 431.82 |
| 5 | 2441823 | 1973-05-20 | 433.23 |
| 6 | 2442253 | 1974-07-24 | 434.97 |
| 8 | 2443118 | 1976-12-05 | 435.05 |
| 9 | 2443558 | 1978-02-18 | 435.93 |
| 10 | 2443982 | 1979-04-18 | 438.01 |
| 11 | 2444431 | 1980-07-10 | 439.67 |
| 13 | 2445319 | 1982-12-15 | 441.2 |
| 14 | 2445744 | 1984-02-13 | 442.37 |
| 15 | 2446201 | 1985-05-15 | 442.93 |
| 16 | 2446647 | 1986-08-04 | 442.84 |
| 18 | 2447539 | 1989-01-12 | 441.85 |
| 19 | 2447978 | 1990-03-27 | 441.71 |
| 20 | 2448416 | 1991-06-08 | 440.77 |
| 21 | 2448861 | 1992-08-26 | 438.36 |
| 23 | 2449730 | 1995-01-12 | 436.15 |
| 24 | 2450164 | 1996-03-21 | 434.62 |
| 25 | 2450620 | 1997-06-20 | 433.78 |
| 26 | 2451034 | 1998-08-08 | 432.72 |
| 27 | 2451450 | 1999-09-28 | 431.32 |
| 28 | 2451877 | 2000-11-28 | 429.58 |
| 29 | 2452328 | 2002-02-22 | 428.67 |
| 30 | 2452758 | 2003-04-28 | 427.99 |
| 31 | 2453184 | 2004-06-27 | 428.09 |
| 32 | 2453608 | 2005-08-25 | 428.42 |
| 33 | 2454022 | 2006-10-13 | 426.89 |
| 34 | 2454459 | 2007-12-24 | 424.91 |
| 35 | 2454889 | 2009-02-26 | 424.41 |
| 36 | 2455304 | 2010-04-17 | 425.07 |
| 37 | 2455749 | 2011-07-06 | 425.74 |
| 38 | 2456152 | 2012-08-12 | 426.7 |
| 39 | 2456570 | 2013-10-04 | 427.73 |
| 40 | 2457000 | 2014-12-08 | 429.66 |
| 41 | 2457444 | 2016-02-25 | 431.95 |
| 42 | 2457870 | 2017-04-26 | 432.81 |
| 43 | 2458305 | 2018-07-05 | 435.38 |
| 44 | 2458749 | 2019-09-22 | 436.98 |
| 45 | 2459190 | 2020-12-06 | 437.68 |
| 46 | 2459628 | 2022-02-17 | 437.83 |
| E | Cycle number from the GCVS4 epoch. |
| O (JD) | Julian date at observed time for maximum. |
| O (Dat) | Same as above, expressed as date. |
| Period | Calculated mean period at cycle number E. |