Cool, @mootari! This is a great solution in that it looks like I might also be able to integrate it with the ‘calculate holidays’ function that I was working on in the notebook.
I was playing around today with moment.js and with its plug-in moment-business-days. I haven’t, however, gotten past the require for the plug-in. Since you and Bryan have already helped me with this issue, I figured I’d dig more into d3-require before raising it again. The patterns you and Bryan provided aren’t working 
moment = require('moment@2.24.0/moment.js', 'moment-business-days@1.1.3')
and
moment = require.alias({'moment-business-days': 'moment'})('moment@2.24.0/moment.js', 'moment-business-days@1.1.3')
both return moment = Ne: invalid module
… so much more to learn! but this is tremendous fun, as I feel a world opening up to me each day.
Thank you and everyone for being so welcoming and patient with me!!