Allow day specification in time conversion

[Phanabani]

This is kind of an edge case, currently some/all of Europe has changed to DST but not America, so it's hard to communicate times in the future when DST has changed. There should be a way of specifying the day (relatively or possibly absolutely as well).

{5pm tomorrow}
{5pm yesterday}
{5pm 2021-11-07}
{5pm sunday}
{5pm next sunday}
{5pm last sunday}