https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=27253 --- Comment #17 from Marcel de Rooy <m.de.rooy@rijksmuseum.nl> --- MariaDB [koha_myclone]> update borrowers set updated_on=COALESCE( NULL, FROM_UNIXTIME(0) ) where borrowernumber=51; ERROR 1292 (22007): Incorrect datetime value: '1970-01-01 00:00:00' for column `koha_myclone`.`borrowers`.`updated_on` at row 1 MariaDB [koha_myclone]> update borrowers set updated_on=COALESCE( NULL, FROM_UNIXTIME(1) ) where borrowernumber=51; Query OK, 1 row affected (0.008 sec) Rows matched: 1 Changed: 1 Warnings: 0 So I would propose to switch to UNIXTIME(1). Note that I would consider this a bug in SQL. Will add a follow-up -- You are receiving this mail because: You are watching all bug changes.