Currently, you have no date property that tells you today's date. This is genuinely a critical function if you are going to compete with other CRMs. How can a sales team set and keep SLAs if they can only look at the time spent in stage retroactively? Please fix it or bring in a "Today's Date" field so people can work around it using a calculated property and some basic automation i.e.
This is a huge hole in the system and is going to cost your partner's deals. A simple addition like this would unlock a lot of potential within the system.