https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=18356 Bug ID: 18356 Summary: Prediction pattern wrong, skips years, for some year based frequencies Change sponsored?: --- Product: Koha Version: master Hardware: All OS: All Status: NEW Severity: normal Priority: P5 - low Component: Serials Assignee: koha-bugs@lists.koha-community.org Reporter: nick@bywatersolutions.com QA Contact: testopia@bugs.koha-community.org CC: colin.campbell@ptfs-europe.com To reproduce: Set a frequency with: Unit: Year Issues per unit: 9 Units per issue: 1 OR Unit: Year Issues per unit: 12 Units per issue: 1 Notice the prediction pattern works for about 1 cycle, then crossed to next year, then jumps a year: No. 82 03/01/2017 No. 83 03/31/2017 No. 84 04/30/2017 No. 85 05/30/2017 No. 86 06/29/2017 No. 87 07/29/2017 No. 88 08/28/2017 No. 89 09/27/2017 No. 90 10/27/2017 No. 91 11/26/2017 No. 92 12/26/2017 No. 93 01/25/2018 No. 94 03/01/2019 WRONG!! No. 95 03/31/2019 No. 96 04/30/2019 No. 97 05/30/2019 No. 98 06/29/2019 No. 99 07/29/2019 No. 100 08/28/2019 No. 101 09/27/2019 No. 102 10/27/2019 No. 103 11/26/2019 No. 104 12/26/2019 No. 105 01/25/2020 No. 106 03/01/2021 WRONG!! Seems to be a problem in some cases when we call: ($year) = Add_Delta_YM($year,$month,$day, $freqdata->{"unitsperissue"},0); As this call will always add a year, it ends up in: /usr/share/perl5/Date/Calc/PP.pm sub DateCalc_add_year_month Where we add $year + $freqdata->{"unitsperissue"} and return 1 if it is greater than 1 Suspecting the pass of $freqdata->{"unitsperissue"} is incorrect -- You are receiving this mail because: You are watching all bug changes. You are the assignee for the bug.