issues: 344019665

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id node_id number title user state locked assignee milestone comments created_at updated_at closed_at author_association active_lock_reason draft pull_request body reactions performed_via_github_app state_reason repo type
344019665 MDU6SXNzdWUzNDQwMTk2NjU= 2307 Pick a certain time 41115380 closed 0     2 2018-07-24T12:41:18Z 2018-07-24T13:38:56Z 2018-07-24T13:38:56Z NONE      

I have a variable with time, lon and lat dimensions.

I can specify longitude (uu = u.where(u.longitude >= 30)), similarly with latitude, but I'm struggling to specify a certain date/time.

Printing the time gives the following output: ```

print u.time <xarray.DataArray 'time' (time: 8)> array(['2018-04-01T00:00:00.000000000', '2018-04-01T06:00:00.000000000', '2018-04-01T12:00:00.000000000', '2018-04-01T18:00:00.000000000', '2018-04-02T00:00:00.000000000', '2018-04-02T06:00:00.000000000', '2018-04-02T12:00:00.000000000', '2018-04-02T18:00:00.000000000'], dtype='datetime64[ns]') Coordinates: * time (time) datetime64[ns] 2018-04-01 2018-04-01T06:00:00 ... Attributes: long_name: time ```

I've tried naming the date by a number like uu = u.where(u.time >= 4) but it gives TypeError: invalid type promotion, and it's not very useful when using a dataset with a huge time dimension.

I'd just like some help figuring out the syntax for specifying days/times.

 
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