Number fields lose focus on Due Date Criteria in Issue Navigator

Steps to reproduce/Current behaviour

When browsing through the Search Issues page and selecting "Due Date" on "More Criteria" drop down, the time fields on "More Than" and "Due in next" doesn't focus with mouse clicks.

Expected behaviour

When clicking on these fields we want them to focus with one mouse click.

Workarounds

1. Browsing to these number fields with "Tab";
2. Double-clicking these number fields;