| E | O (JD) | O (dat) | Period |
| -23 | 2447240 | 1988-03-19 | 425.91 |
| -22 | 2447666 | 1989-05-19 | 424.86 |
| -21 | 2448111 | 1990-08-07 | 425.51 |
| -20 | 2448524 | 1991-09-24 | 426.32 |
| -19 | 2448939 | 1992-11-12 | 426.87 |
| -18 | 2449375 | 1994-01-22 | 428 |
| -17 | 2449790 | 1995-03-13 | 428.69 |
| -16 | 2450228 | 1996-05-24 | 429.63 |
| -15 | 2450661 | 1997-07-31 | 431.6 |
| -14 | 2451090 | 1998-10-03 | 431.86 |
| -13 | 2451535 | 1999-12-22 | 430.73 |
| -12 | 2451959 | 2001-02-18 | 430.34 |
| -11 | 2452397 | 2002-05-02 | 428.58 |
| -10 | 2452832 | 2003-07-11 | 427.21 |
| -9 | 2453243 | 2004-08-25 | 424.91 |
| -8 | 2453658 | 2005-10-14 | 421.97 |
| -7 | 2454095 | 2006-12-25 | 421.43 |
| -6 | 2454511 | 2008-02-14 | 422.22 |
| -5 | 2454938 | 2009-04-16 | 420.75 |
| -4 | 2455340 | 2010-05-23 | 420.19 |
| -3 | 2455747 | 2011-07-04 | 420.3 |
| -2 | 2456197 | 2012-09-26 | 419.56 |
| -1 | 2456650 | 2013-12-23 | 420.09 |
| 0 | 2457013 | 2014-12-21 | 419.81 |
| 1 | 2457434 | 2016-02-15 | 419.99 |
| 2 | 2457876 | 2017-05-02 | 419.49 |
| 3 | 2458286 | 2018-06-16 | 417.53 |
| 4 | 2458715 | 2019-08-19 | 417.17 |
| 5 | 2459122 | 2020-09-29 | 421.5 |
| 6 | 2459542 | 2021-11-23 | 420.2 |
| 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. |