| E | O (JD) | O (dat) | Period |
| -6 | 2438293 | 1963-09-20 | 419.32 |
| -5 | 2438705 | 1964-11-05 | 419.36 |
| -4 | 2439119 | 1965-12-24 | 420.6 |
| -2 | 2439972 | 1968-04-25 | 420.55 |
| -1 | 2440384 | 1969-06-11 | 420.1 |
| 0 | 2440803 | 1970-08-04 | 418.93 |
| 2 | 2441643 | 1972-11-21 | 420.18 |
| 3 | 2442082 | 1974-02-03 | 420.48 |
| 4 | 2442490 | 1975-03-18 | 420.51 |
| 5 | 2442900 | 1976-05-01 | 420.95 |
| 12 | 2445820 | 1984-04-29 | 421.08 |
| 19 | 2448804 | 1992-06-30 | 421.26 |
| 22 | 2450062 | 1995-12-10 | 421.28 |
| 23 | 2450480 | 1997-01-31 | 421.65 |
| 24 | 2450922 | 1998-04-18 | 421.89 |
| 25 | 2451333 | 1999-06-03 | 422.16 |
| 26 | 2451762 | 2000-08-05 | 419.21 |
| 27 | 2452173 | 2001-09-20 | 418.27 |
| 28 | 2452589 | 2002-11-10 | 418.08 |
| 29 | 2452999 | 2003-12-25 | 417.47 |
| 30 | 2453419 | 2005-02-17 | 418.47 |
| 31 | 2453830 | 2006-04-04 | 419.01 |
| 32 | 2454254 | 2007-06-02 | 420.18 |
| 33 | 2454686 | 2008-08-07 | 420.66 |
| 34 | 2455100 | 2009-09-25 | 421.44 |
| 35 | 2455529 | 2010-11-28 | 421.33 |
| 36 | 2455947 | 2012-01-20 | 420.99 |
| 37 | 2456369 | 2013-03-17 | 419.79 |
| 38 | 2456782 | 2014-05-04 | 418.42 |
| 39 | 2457211 | 2015-07-07 | 417.44 |
| 40 | 2457624 | 2016-08-23 | 416.73 |
| 41 | 2458040 | 2017-10-13 | 416.34 |
| 42 | 2458452 | 2018-11-29 | 415.78 |
| 44 | 2459284 | 2021-03-10 | 415.37 |
| 45 | 2459694 | 2022-04-24 | 414.16 |
| 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. |