We're thrilled that we will get support for datetime manipulation and especially datetimeDiff. One of the most common usecases for it being to compute time elapsed since something happend like a user signing up or its first purchase .
I went through the release note , related github issues like this one or the list of supported expressions but couldn't see if a function like today() or time() will be introduced as well to support this use case. I would avoid having to add current time to all my relevant model to hack this around if possible.
We're running Metabase 0.44 on Cloud using PostgreSQL and Snowflake as datasources.