Create customer calender in Metricflow

The problem I’m having

We just upgraded to a verion 1.6.2 and had to migrate from dbt-metrics to Metricflow. We have defined a customer calender with customer time grains, but we couldn’t make it work with Metricflow. In dbt-metric we were able to define a customer calender.

What I’ve already tried

We have already tried to add a semantic model with the name of metricflow_time_spine for our custom calender. Metricflow does not seem to pick up the time grains we have defined.

Is there anyone who was able to use a customer calender within Metricflow or is this a feature that is not implented yet?