Use time spines to determine metric_time grain in no-metric queries

metricflow-semantics/metricflow_semantics/model/semantics/linkable_spec_resolver.py

@@ -40,6 +40,7 @@
 from metricflow_semantics.model.semantics.linkable_element_set import LinkableElementSet
 from metricflow_semantics.model.semantics.semantic_model_join_evaluator import SemanticModelJoinEvaluator
 from metricflow_semantics.specs.time_dimension_spec import DEFAULT_TIME_GRANULARITY
+from metricflow_semantics.time.time_spine_source import TimeSpineSource
 
 if TYPE_CHECKING:
     from metricflow_semantics.model.semantics.semantic_model_lookup import SemanticModelLookup
@@ -124,6 +125,7 @@ def __init__(
         # Sort semantic models by name for consistency in building derived objects.
         self._semantic_models = sorted(self._semantic_manifest.semantic_models, key=lambda x: x.name)
         self._join_evaluator = SemanticModelJoinEvaluator(semantic_model_lookup)
+        self._time_spine_sources = TimeSpineSource.create_from_manifest(self._semantic_manifest)
 
         assert max_entity_links >= 0
         self._max_entity_links = max_entity_links
@@ -464,7 +466,8 @@ def _get_metric_time_elements(self, measure_reference: Optional[MeasureReference
                 time_dimension_reference=measure_agg_time_dimension_reference,
             )
         else:
-            defined_granularity = DEFAULT_TIME_GRANULARITY
+            # If querying metric_time without metrics, will query from time spines.
+            defined_granularity = min(self._time_spine_sources.keys())
 
         # It's possible to aggregate measures to coarser time granularities (except with cumulative metrics).
         possible_metric_time_granularities = tuple(