OptaPlanner supports continuous planning (see my latest video), which is the ability to use a "sliding planning window". It also supports the use of java.time,

OptaPlanner supports continuous planning (see my latest video), which is the ability to use a "sliding planning window". It also supports the use of java.time, which means it supports LocalDateTime, OffsetDateTime, ZonedDateTime, and all other time related functionality that deals with implementing the insane intricacies of time for you. For example: if a shift runs from you 2:00 UTC to 10:00 UTC and employees from different timezones can furfil it and Daylight Saving Time changes for one of those employee's regions, you can write a constraint to detect that and avoid assigning the DST-affected employee that night.