This does currently not exist, you would have to create your own today's date property. This thread outlines different approaches (see also the replies and experiences of other users).
I'm Dave from the hapily support team! We just launched an app called Tick Tock Today that creates a today's date property for your objects. It's available on the HubSpot Marketplace.
I've formulated some different ways to use the property. Including for your use case! I documented how to create a "time between" property in this blog post here.
If you have any questions, feel free to reach out. I'd be happy to hop on a call with you!
I created a Custom property "Today's Date" - it appears to work as advertised. Then I used it in a Calculated Date field to create a countdown on the number of days for a Trial. Imagine my chagrin when I discovered that AFTER the end date, the calculated property started counting up from the end date instead of giving a negative value ... I figured out that this is because the property is a date, not a numeric property.
This does currently not exist, you would have to create your own today's date property. This thread outlines different approaches (see also the replies and experiences of other users).