This includes specification of time information via a parameter time with a value of time stamp in UTC. For instance the above URL is requesting time for '2017-01-01T6:00:00.000Z' (UTC time).
Therefore I looked into programmatically adding the layer via ArcPY in the print geoprocessing service. I found that ArcMAP desktop 10.7.1 as well as ArcGIS PRO (2.x) support specification of custom parameters for WMS service layer manually as described in the following links (PRO- https://pro.arcgis.com/en/pro-app/help/data/services/add-wms-services.htm and desktop http://desktop.arcgis.com/en/arcmap/latest/map/working-with-arcmap/connecting-to-gis-servers.htm).
However, I would like to programmatically change a custom parameter (which would be time in my case) specified for this WMS service layer, using ArcPY to circumvent the webmap printing problem and I am unable to locate a function that will let me change it. I have already looked at layer.dataSource and layer.connectionProperties but find these to be null for a saved wms service layer. I was hoping to use updateConnectionProperties method. Has anyone encountered a similar issue, and can guide me on a solution to achieve printing via ArcMap 10.7.1 or PRO by changing the custom parameter of an existing wms layer dynamically?