How to forecast product/item sales next one week using Xgboost regressor
Yes, you cannot pass in a datetime object as a feature to XGboost Regressor, because it isn't time-series forecasting tool such as ARIMA. 

Instead, you create various features from the timeseries object such as year, month, day of month, day of week, number of days until public holiday etc. All of these are of type int. Drop the timeseries column. 

When you're passing in the test data, you convert the datetime object into the above features.