That's because it's sorting ascending. If you want 29 after 30, then you need descending.
SELECT measurements.title as Tittel, routines.value as Verdi, CONVERT(VARCHAR(10),routines.date,103) as Dato, convert(VARCHAR(10), routines.time, 108) as Tid, pools.name as Basseng, emps.user_name as Ansatt
FROM routines, measure_routine, measurements, pools, emps
WHERE routines.id = measure_routine.routine_id
AND measure_routine.measure_id = measurements.id
AND (measurements.title Like 'T_%') AND measure_routine.pool_id=pools.id AND routines.emp_id=emps.id
AND Date between '2014-04-29' and '2014-04-30'
order BY routines.date desc, routines.time desc