Dates and times are essential elements in most Excel workbooks. However, entering dates and times improperly can cause major issues down the line. Without best practices, dates may not sort chronologically, time values could be interpreted incorrectly, and your ability to analyze date-based data is limited. Fortunately, following a few guidelines can ensure your dates and times remain accurate and easy to work with in Excel.
Using consistent date formats, entering dates and times as numeric values, avoiding text entries, leveraging formulas for calculations, and checking system settings are key steps. In this article, we will explore these date and time best practices in detail. Whether you need to enter a few dates or build complex time-based models, these guidelines will set you up for success. By the end, you will have the knowledge to work seamlessly with dates and times in Excel. Let’s get started!
Best Practices for Entering Dates and Times in Excel
Use a Consistent Date Format
When entering dates into Excel, it’s important to use a consistent date format. The default format in Excel is m/d/yy (e.g. 3/14/22). You can customize the date format by selecting the cells, opening the Home tab, clicking the Number Format dropdown, and choosing the desired format.
Some common formats are:
- m/d/yyyy – 03/14/2022
- d-mmm-yy – 14-Mar-22
- dddd, mmm d, yyyy – Monday, Mar 14, 2022
Pick one date format and use it consistently throughout your workbook. Avoid mixing formats like m/d/yy and mm/dd/yyyy in the same columns.
Enter Dates as Serial Numbers
You can also enter dates as serial numbers. By default, Excel stores date as numbers – with 1 being January 1, 1900. So January 2, 1900 would be the number 2. This makes it easy to add and subtract dates for date math calculations. To see the underlying serial number for a date, format the cells as General rather than Date.
Entering dates as serial numbers can help avoid issues if your workbook is opened in a different locale where the date order might be interpreted differently.
Enter Times as Decimal Values
Excel stores times as decimal values, with .00 being 00:00 (midnight) and .50 being 12:00 noon. So 8:30 AM would be entered as 0.375 (8 hours + 30 minutes / 60 minutes per hour = 0.375). And 4:45 PM would be 0.7031 (16 hours + 45 minutes / 60 minutes per hour = 0.7031). Entering times as decimals provide maximum accuracy and avoid potential translation issues between locales using different time formats.
Avoid Entering the Date and Time as Text
Sometimes dates and times get entered as text values rather than dates or times. For example, 3/15/22 typed in a cell without formatting it as a date. This prevents you from manipulating the dates, such as finding days between dates or adding and subtracting time values. Ensure dates and times are formatted properly as Date and Time. If not, convert the cells using Paste Special to convert them. Avoid leaving them as unformatted text entries.
Use Formulas for Date and Time Math
To add, subtract, compare, or extract date and time components, use formulas like:
- =DATE(year,month,day) to make a date from parts
- =YEAR(), =MONTH(), =DAY() to extract parts of a date
- =DATEVALUE() to convert text strings into dates
- =TIME() to make a time from hours, minutes, seconds
- =TIMEVALUE() to convert text times into time values
This makes your date and time data easier to work with compared to doing the math yourself.
Adjust System Settings Accordingly
Depending on your locale and system settings, Excel may default to d/m/yy, dd/mm/yy, or other date formats.
Go to Control Panel > Region and Language > Additional Settings to verify date and time settings.
Adjust as needed to ensure proper interpretation of any manually entered dates and times in your Excel workbooks.
Link Date Columns to Year Columns
For year-over-year analysis, link the year value from dates to its own column. Use the YEAR() formula to extract the year from a date column into a new Year column. That way you can group, filter, and pivot based on the year without affecting the underlying date column.
Following these best practices will help you work accurately and efficiently with dates and times in Excel. Consistent formats, utilizing formulas, and sanity-checking system settings based on your locale are key to success.
The Bottom Line
In summary, mindful planning, disciplined consistency, and proactive verification are key when entering dates and times in Excel. Keep these best practices in mind and you will be able to handle date- and time-based data with confidence. Your Excel skills will become more robust and your analysis more trustworthy.
Now that you are armed with these guidelines, you can enter dates and times in your workbooks like a pro. The time you spend upfront following these standards will be rewarded every time you leverage the date and time data in reports and models down the road.
