Blockchain web interface doesn't have milliseconds, but blockchain api has.
Does it, where/how?
Also the API has not. But you can use the time in millisecond for your selection:
Blocks for one day:
https://blockchain.info/de/blocks/$time_in_milliseconds?format=json
See:
https://blockchain.info/de/api/blockchain_apiBut i am not sure, if this really helps. The other way round would be much more comfortable: Select with a hash and get the time in ms.
Is there any API? I didn't found.