The date field I want to use as a basis for searching was added through the studio, so it is not a search based on a time stamp automatically created by Sugar
You can enable date range search with a vardef extension.
In <sugarcrm>/custom/Extension/modules/<your module>/Ext/Vardef/<your filename>.php
$dictionary['<your module>']['fields']['<the date field name>']['enable_range_search'] = true;
$dictionary['<your module>']['fields']['<the date field name>']['options'] = 'date_range_search_dom';
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