How to compare just the date part of a dateTime field?
I'm not 100% sure I'm reading your question correctly, but here goes:

I'm assuming you're getting the date as a string as a route param (maybe you shouldn't call it date though, as that is a function in Twig), I'll call that dateTime here:


{% set dayAfter = date(datetime) | date_modify('+1 day') | date('Y-m-d') %}
{% set entries = craft.entries.section('events').startDate(['and', '&gt;= '~datetime, '&lt; '~dayAfter]) %}


What's happening is you get a date, then you add one day to that date, then find all entries that have startDate greater than or equal to the date you're looking for, and less than the day after, thus getting all entries for that particular date.

This might be over engineered though, and there might be a way simpler way to do this...