The (admin) change timestamp dialog was unusable on mobile devices as the button is hidden behind the date drop-down.
I mitigated this on my forum using the following CSS, which right-aligns buttons in the footer of modal dialogs
.modal-footer .btn-primary {
float: right;
}
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techAPJ
(Arpit Jalan)
2
I added a new class for relevant modal footer and added the CSS you suggested.
https://github.com/discourse/discourse/commit/0bdced165a1a9213cd720e651b79649698bad8f5
Thanks for bringing this in our notice @ChrisBeach 
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