@sdetweil After doing more reading, I found the modified .js file on GitHub. Replace original ~/MagicMirror/modules/calendar_monthly/calendar_monthly.js with this one (not mine) and edit ~/MagicMirror/config/config.js to load the module as follows:
{
disabled: false,
module: 'calendar_monthly',
position: "top_left",
config: {
showHeader: true,
// cssStyle: "",
monthOffset: 0,
}
},
That will show the current month. If you want the previous month, then add the module again before the current month and change monthOffset to -1. For the next month, add the module again after the current month and change monthOffset to 1.
If you want current month plus the next two months, then add the module three times with monthOffset set to 0, 1, and 2.