By popular demand, we’ve decided to put together a set of topics that coaches & competitors in the Texas High School UIL Computer Applications contest should know in order to be competitive at state and regional levels.  This list of 10 topics will focus more on advanced formulas and applications of the programs than it will on basics (e.g. basic math formulas in Excel, letter formats and other Word templates, etc).  We covered the first item a while back in our blog post on IF statements…and conditional IF statements, SUMIF, COUNTIF, etc.  This blog post introduces the second item: Times and Dates in Excel.

Times and dates in Excel work the same way that they do in Access (with some minor differences – e.g. dates are set off by pound signs in Access formulas whereas they’re set off by quotes in Excel formulas).  To understand them, the key is grasping that every time and date (and time/date combination) is saved as a number in Excel (or Access).

 Keeping this in mind, the number 1 is equivalent to midnight on January 1, 1900.  The number 2 is equal to midnight on January 2, 1900.  Thus, each increment of one amounts to one full day.  As you might imagine, decimals follow this same pattern.  If you add 1/2 to an existing number, you add 12 hours.  So, 1.5 is equal to noon (12p) on January 1, 1900.  Similarly, 1.75 is equal to 6p on January 1, 1900.

If you’d like additional help with times and dates, you should definitely check out our video tutorial on them that covers the nuts and bolts of how dates/times work in addition to a smattering of formulas that involve dates and times.  You can preview it here: