10.5 Bitcoin blockchain cannot provide fine grain timestamping
Wasabi Wallet
Bitcoin miners control block timestamps without enforcement, enabling manipulation at any sub-day granularity. Hour or minute-level timestamping breaks against adversarial miners when timestamps are economically valuable. Open Timestamps avoids this by rounding to daily precision, the only defensible granularity without block inspection.

https://relay.towardsliberty.com/f29eabd651e9e493fb8b1ebe139b5995cb44f111a6f8ab35f38a4a6948fd027a.mp4