More Date Functions; AND & OR Functions

Important Date Functions in Excel

• Introduction to several important date functions in Excel:

  • Year Frac

  • Date, Day, Month, Year Functions

Year Frac Function

• Definition: The YEARFRAC function returns the proportion of the year between two given dates.

  • Parameters:

  • Start Date: The beginning date from which to calculate the fraction of the year.

  • End Date: The ending date to which the calculation extends.

  • Basis (optional): Represents the number of days per month and year used in the calculation of the fraction of the year.

• Default value for Basis: If omitted, defaults to a calculation of 30 days per month and 360 days per year, defined as:

  • $ext{Basis} = rac{30}{360}$

• Application: Useful in financial modeling for forecasting future cash flows or obligations for a fraction of the year.

  • Particularly relevant for calculating a stub year fraction—where one needs to articulate a portion of the year without calculating it entirely.

• Examples and Usage:

  • Demonstration involves calculating from 12/31/2008 to 06/15/2019 without specifying a basis to utilize default settings.

  • Results compute to approximately 45% of the year.

Date Functions

• Overview of four key functions:

  • Date: Combines year, month, and day elements into a valid date.

  • Day: Extracts the day from a date serial number.

  • Month: Extracts the month from a date serial number.

  • Year: Extracts the year from a date serial number.

Date Function

• Requires three parameters:

  • Year

  • Month

  • Day

• Example Usage:

  • To create a valid date:

  • Input: =DATE(2015, 12, 31) results in a formatted date.

Day Function

• Definition: Extracts the day of the month (as a number) from a date serial number.

• Example Usage:

  • Input the cell of a date to extract the day: =DAY(C4), which gives 31 from the date 12/31/2015.

Month Function

• Definition: Extracts the month from a date serial number.

• Example Usage:

  • Input the cell containing a date: =MONTH(C4), which will output 12 from the date 12/31/2015.

Year Function

• Definition: Extracts the year from a date serial number.

• Example Usage:

  • Extract year by referencing: =YEAR(C4)+1 increments year to 2016, demonstrating adjustments.

Operational Efficiency with Date Functions

• Key Point: The combination of Date, Day, Month, and Year functions can create dynamic date columns, albeit less straightforward than using EOMONTH.

• This method, while more cumbersome, provides an understanding of how to manipulate date components programmatically.

Logical Functions - AND and OR

• Introduction to AND and OR functions in Excel:

  • Part of logical function family, which also includes IF and IFERROR functions.

AND Function

• Definition: Evaluates conditions and returns TRUE if all arguments are TRUE, otherwise returns FALSE.

• Usage Example:

  • Replacing nested IF statements with an AND function for eligibility to vote.

  • Syntax: =IF(AND(condition1, condition2), result_if_true, result_if_false).

OR Function

• Definition: Evaluates conditions and returns TRUE if at least one argument is TRUE; returns FALSE if all are FALSE.

• Usage Example:

  • Syntax: =IF(OR(condition1, condition2), result_if_true, result_if_false).

Practical Applications of AND and OR Functions

• Scenario Application: Using AND or OR to analyze employee eligibility for a raise based on multiple criteria (length of employment and performance rating).

  • Example for AND:

  • Raise if on the job for five years AND performance rating is 8 or higher.

  • Example for OR:

  • Raise if on the job for five years OR performance rating is 8 or higher.

• Formulation of Result:

  • For a raise, calculate new salary based on original salary multiplied by either a growth factor:

  • Example Formula:
    $ext{New Salary} = ext{Original Salary} imes (1 + 0.05)$

Summary

• Reviewed date functions: YEARFRAC, DATE, DAY, MONTH, YEAR, alongside logical functions AND and OR.

• Encouragement to apply learning through hands-on experimentation within Excel to reinforce understanding of functions and their applications in real-world scenarios.