| E | O (JD) | O (dat) | Period |
| -30 | 2425120 | 1927-08-27 | 397.65 |
| -28 | 2425900 | 1929-10-15 | 397.77 |
| -23 | 2427890 | 1935-03-28 | 397.74 |
| -21 | 2428690 | 1937-06-05 | 397.99 |
| -19 | 2429490 | 1939-08-14 | 398.54 |
| -16 | 2430680 | 1942-11-16 | 398.76 |
| -13 | 2431875 | 1946-02-23 | 399.42 |
| -12 | 2432270 | 1947-03-25 | 399.8 |
| -11 | 2432680 | 1948-05-08 | 399.29 |
| -10 | 2433100 | 1949-07-02 | 397.23 |
| -9 | 2433490 | 1950-07-27 | 396.88 |
| -8 | 2433886 | 1951-08-27 | 396.74 |
| -7 | 2434285 | 1952-09-29 | 396.4 |
| -6 | 2434658 | 1953-10-07 | 396.29 |
| 8 | 2440210 | 1968-12-19 | 396.21 |
| 15 | 2443000 | 1976-08-09 | 396.43 |
| 16 | 2443400 | 1977-09-13 | 396.67 |
| 19 | 2444570 | 1980-11-26 | 396.94 |
| 23 | 2446172 | 1985-04-16 | 397.36 |
| 24 | 2446564 | 1986-05-13 | 397.66 |
| 25 | 2446974 | 1987-06-27 | 398.04 |
| 26 | 2447381 | 1988-08-07 | 398.89 |
| 27 | 2447775 | 1989-09-05 | 399.81 |
| 28 | 2448160 | 1990-09-25 | 398.95 |
| 29 | 2448558 | 1991-10-28 | 398.42 |
| 30 | 2448978 | 1992-12-21 | 397.67 |
| 31 | 2449380 | 1994-01-27 | 396.84 |
| 32 | 2449760 | 1995-02-11 | 396.8 |
| 33 | 2450153 | 1996-03-10 | 396.67 |
| 34 | 2450553 | 1997-04-14 | 396.66 |
| 35 | 2450954 | 1998-05-20 | 396.68 |
| 36 | 2451338 | 1999-06-08 | 397.63 |
| 37 | 2451740 | 2000-07-14 | 397.61 |
| 38 | 2452137 | 2001-08-15 | 397.22 |
| 39 | 2452550 | 2002-10-02 | 396.55 |
| 40 | 2452951 | 2003-11-07 | 396.37 |
| 41 | 2453346 | 2004-12-06 | 396.18 |
| 42 | 2453716 | 2005-12-11 | 395.91 |
| 43 | 2454119 | 2007-01-18 | 395.77 |
| 44 | 2454513 | 2008-02-16 | 396.37 |
| 45 | 2454916 | 2009-03-25 | 397.43 |
| 46 | 2455307 | 2010-04-20 | 399.06 |
| 47 | 2455715 | 2011-06-02 | 400.1 |
| 48 | 2456111 | 2012-07-02 | 399.2 |
| 49 | 2456525 | 2013-08-20 | 398.56 |
| 50 | 2456917 | 2014-09-16 | 396.97 |
| 51 | 2457322 | 2015-10-26 | 395.76 |
| 52 | 2457709 | 2016-11-16 | 394.29 |
| 53 | 2458095 | 2017-12-07 | 393.39 |
| 54 | 2458493 | 2019-01-09 | 391.97 |
| 55 | 2458874 | 2020-01-25 | 391.52 |
| 56 | 2459271 | 2021-02-25 | 390.64 |
| 57 | 2459667 | 2022-03-28 | 391.4 |
| 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. |