With Microsoft Band and Windows Phone app I want to get from the MSBand the steps taken in the current day. Today, when I subscribe to the pedometer, the totalsteps attribute returns the steps taken overall. For example, my MSBand is returning 1M 444K steps. Does anyone knows how to get only the total daily steps?
The Band SDK does not expose the number of steps (by its internal count) taken by the wearer in the current day. The closest approximation to your goal would be to register a time-triggered background task that retrieves a pedometer sensor reading every n-number of minutes/hours and then calculates the number of steps taken on the current day based on a delta between successive readings. Obviously this implies a certain margin of error, based on how often (and when) that background task executes.
(On Windows Phone (8.1), for example, a background task can execute at most every ~30 minutes and isn't necessarily aligned to any given minute of the hour, which means steps could be attributed to one day or the next based on which side of the "midnight" hour the task happens to run.)