Currently I am splitting my data by subtracting days from DateTime.Now

```
GetVolumeByDate(DateTime.Now.AddDays(-3), DateTime.Now.AddDays(-2))
GetVolumeByDate(DateTime.Now.AddDays(-2), DateTime.Now.AddDays(-1))
GetVolumeByDate(DateTime.Now.AddDays(-1), DateTime.Now))

```

This shows all data from the last 24 hours as today and the 24 hour period before that as yesterday. What I'm looking to do is split the days at midnight. So today is from the 12am until now and yesterday is from 12am to the 12am before. What is the simplest way to do that?