Add validation to parameters
Display correct month when only  is specified
Add new parameter set taking DateTime as input
Accept date from pipeline
Specify default parameter set name
Rename  to  and allow arbitrary number of neighbouring months
Highlight input date on calendar instead of current date
Pass array of months to Show-Months instead of start date and count
Modify test script
Support multiple dates from pipeline
Display only unique months
Add additional test case for multiple pipeline inputs
Mark all days specified on input
Add test related to marking subsequent days
Highlight spaces between subsequent marked days