Typically collaboration works best when a team shares the same working hours to maximize the communication time that they have with each other. However, there are exceptions to the rule where that level of collaboration isn’t necessary or an individual holds a role that benefits from them working off hours from the rest of the group and as such they provide greater 24 hour coverage for the team - a support role for example.
Therefore if a role doesn’t require the person who holds it to work the same hours as the company works, or a team feels that this isn't necessary and they are achieving their goals, and, whoever that team reports to agrees, then that team can decide what hours they, or an individual within the team works as long as they have someone available during our business hours and they are represented at our regular gatherings.
And we are open to both working part time at a role or splitting a role between one or more part time people. It all depends on the situation and if it works for the team in question.