Monthly Archives: March 2021

US Daylight Saving Time Date Calculation in Excel

Posted on 14-March-2021 by mathscinotes

I recently had a situation where I needed to correct a number of date/time values because they did not take into account Daylight Saving Time (DST). To be specific, some transactions from China were recorded assuming a fixed time offset with respect to US Central Standard Time. Because of DST, this is not always the case. My customer only works in Excel, so the work was done in Excel. Continue reading →

Posted in Excel | 6 Comments

Taffy 3 Total Displacement vs Yamato Using R

Posted on 10-March-2021 by mathscinotes

I was watching a documentary on the Battle Off Samar on my favorite Youtube naval channel called Drachinifel. During this show, Drachinifel stated that the battleship Yamato displaced more tonnage than the entire Task Group 77.4.3 (call sign Taffy 3) defense force. I found this a remarkable statement and one that I could verify using a little bit of web scraping. Because one of the students I tutor use R, I thought this would be a good exercise to implement using R and Rmarkdown (a great report generation tool). Continue reading →

Posted in History Through Spreadsheets, Naval History | 2 Comments