JQL extensions allow you to search for issues depending on whether or not they currently have a timer running, or depending on their accumulated hours.
Find Issues by User and Timeframe
You can use the worklogAuthor and worklogDate fields with JQL date/time functions to return issues that have been worked on during a time period.
This query returns a list of all issues that have work reported for the current week.
Use this query to see issues that the current user worked on this week.
JQL Date/Time Functions
Find Issues with a Running Timer and Issues with Relative Acculated Hours are only available in Clockwork Pro.
Find Issues with a Running Timer
Use the timerIsRunning extension to find issues that currently have a running timer. The example below will return all issues in the HC project that have at least one timer running.
Find Issues with Relative Accumulated Hours
The allTimersInHours extension returns a numeric value that can be used in relative expressions. The example below will return all issues in the HC project that more than 10 accumulated hours.