[Feature] Allow variables in --start-time and --end-time

[siljamardla]

Is this your first time submitting a feature request?

• I have read the expectations for open source contributors
• I have searched the existing issues, and I could not find an existing issue for this feature
• I am requesting a straightforward extension of existing metricflow functionality, rather than a Big Idea better suited to a discussion

Describe the feature

MetricFlow has validation rules on --start-time and --end-time.
If you enter something else, e.g. a string or variable, you will get an

Error: Invalid value for '--start-time': must be valid iso8601 timestamp

For the cases when we don't query, but simply compile the code, it would be very good to be able to override this validation. Specifically, we want to use variables in the output query. Example:

mf query --metrics my_metric --start-time DATE('{{ var("data_interval_start") }}') --explain

Describe alternatives you've considered

Compile the code and do a find-and-replace.

Who will this benefit?

No response

Are you interested in contributing this feature?

No response

Anything else?

No response