Change Details

``` Also switch to chrono based types. ``` Partial backport of core PR17270: https://github.com/bitcoin/bitcoin/pull/17270/commits/64e1e022cedf6776c5dffd488ca2e766adca5dc3

``` Also switch to chrono based types. ``` Partial backport of core [[https://github.com/bitcoin/bitcoin/pull/17270 | PR17270]]: https://github.com/bitcoin/bitcoin/pull/17270/commits/64e1e022cedf6776c5dffd488ca2e766adca5dc3

``` Also switch to chrono based types. ``` Partial backport of core [[https://github.com/bitcoin/bitcoin/pull/17270 | PR17270:]]: https://github.com/bitcoin/bitcoin/pull/17270/commits/64e1e022cedf6776c5dffd488ca2e766adca5dc3