Manager allows to create custom fields for many entities but they are all of type string. I have created several custom fields which need a date.
To be able to create a custom field of type date would be handy. It does not have to be stored as date, since i have seen that custom fields are stored as hashmap, so probably as key value pair. It does not even have to be validated, just a calendar popup when you choose a custom field of type date would be enough.