How to display a half weekly chart


Anyone know how to display a half weekly chart?

The database is one minute based (Interactive Brokers). So far I've tried entering things like '15h' (2.5 x 6 hour trading days), '60h' (2.5 x 24 hours), '3600m' (2.5 x 24 x 60 minutes) into the little symbol/timeframe window on the tool bar. But those values produce a normal one or two day day bar chart.
'2d' and '3d' produce correct results but I can't crack the '2.5d' combination!

Any ideas?