Change field type outside of a shard group boundary

From time to time we need to change our Influx schema, and we set our shard group duration to 1d so that we get a fresh shard every day at midnight UTC. The importers that run on the new day can write data under a new schema that’s guaranteed not to conflict with existing data.

However we’re importing one set of data 23 hours per day, starting 10pm UTC. It seems that the shard group setup means this importer can never change its schema, because there will always be some existing data when it starts at 10pm.

Is there a way we can change our setup to avoid this problem, or to otherwise work around it? Can we have shards that start at 10pm daily instead of midnight? Or can we tell Influx explicitly to start a fresh set of shards, to coincide with the data we’re trying to write under the new schema?