in packages/opentelemetry-cloud-monitoring-exporter/src/transform.ts [180:192]
value: transformNumberValue(
metric.descriptor.valueType,
dataPoint.value
),
interval: {
// Add start time for non-gauge points
...(metric.dataPointType === DataPointType.SUM && metric.isMonotonic
? {
startTime: new PreciseDate(dataPoint.startTime).toISOString(),
}
: null),
endTime: new PreciseDate(dataPoint.endTime).toISOString(),
},