The dateutil library is awesome at this (`pip install python-dateutil`), and I think would get rid of the sleep. Here's an example that I think achieves your goals:
```python
from datetime import datetime
from dateutil.relativedelta import relativedelta

dt = datetime.utcnow()
# Add enough minutes to get to the nearest scheduleable interval
# Pad with 5 minutes, so 10 - minute % 5?
dt += relativedelta(minutes=10 - (dt.minute % 5))
# This date format is terrible, USA needs to stop it.
# I think the form would also accept "%d-%d-%d" % (dt.year, dt.month, dt.day), but I'm not sure.
date = "%d/%d/%d" % (dt.month, dt.day, dt.year)
print date, dt.hour, dt.minute
```