The Pay Period Anchor Date was a free-text Char. Make it a fields.Date (date picker) persisted manually in get_values/set_values as 'YYYY-MM-DD' under fusion_clock.pay_period_start (res.config.settings Date fields don't round-trip via config_parameter in Odoo 19). Reader code unchanged. Bump 3.15.1 -> 3.15.2. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>