Left Join 3 tables into ONE in Mysql
Do not use functions on your columns you are comparing against, as that prevents the query from using any indexes you may have.

Start with this:

SELECT employees.eno,employees.ename,employees.dept,attendanceIn.attIn AS attIn,attendanceOut.attOutAS attout
FROM employees 
LEFT JOIN attendanceIn ON employees.eno=attendanceIn.eno 
LEFT JOIN attendanceOut ON employees.eno=attendanceOut.eno
WHERE attendanceIn.puchtime &gt;= '2016-07-01 00:00:00'
AND attendanceIn.puchtime &lt; '2016-07-02 00:00:00'
AND attendanceOut.puchtime &gt;= '2016-07-01 00:00:00' 
AND attendanceOut.puchtime &lt; '2016-07-02 00:00:00' 
GROUP BY eno 
ORDER BY eno ASC


If you still need performance improvements, provide SHOW CREATE TABLE tablename statements for all your tables in this query.