CalendarXL

CalendarXL - latest addition to the SpiderXL Add-ins suite - brings intuitive and powerful date and calendar calculation functions into Microsoft Excel.
CalendarXL is a perfect compliment to NumXL Add-in financial time series analysis software: Strategists and analysts often desire to exploit the information embedded in the date component of a time series to uncover calenderical drivers in their returns and/or volatilities.

For instance: Are returns/volatilities significantly different for those days that precede or succeed a long weekend or fall on economic data release days?
Does the number of trading days in a holding period (e.g., weekly, bi-weekly, etc.) affect the returns or volatility?
Are returns/volatilities significantly different on days that overlap economic data (e.g., CPI, Employment report, etc.) announcements?
You can use CalendarXL functions either manually, by typing them into your workbook cells, or by using the CalendarXL menu and toolbar.
Once a spreadsheet is created with CalendarXL using one data set, running the same analysis for different data (or the same but with new observations) is as simple as copying and pasting.