Add all the ingredients to a blender and puree until smooth.
So first, I've recommended 1-2 dates as this can vary based on the size of your dates and also the sweetness level you prefer. This smoothie is more on the (naturally) sweet side as opposed to a green or vegetable-based smoothie. So this is really up to you and you could even omit the dates, if you like.
As I said above, the mandarins are seedless. So after peeling you really can just plop them into the blender. If you want to juice them instead you can, but I like to keep the whole fruit intact as it aids your body in using the natural sugars found in the fruit.
If you are doing the #weekdayweekend challenge with us, then you know that we're opting to go dairy-free during the week, so here you'll want to stick with a dairy-free milk. But if you like, you can use dairy milk here instead. I just recommend whatever you choose, keep it unsweetened.
And speaking of dairy, if you are not participating or don't care about keeping this dairy-free, an option for adding some protein is to stir a little greek yogurt into the smoothie (or you can blend it in). It will add creaminess, a slight tang, but mostly some added protein. If you want to keep it dairy-free, you can always add a little protein powder of your choice.