subtract

Subtract numerics from mondates. 
 When units = "months" and the <code>numeric</code> is a whole number
 the result has the same 
 day of the month subject to the number of days in the month,
 thus abandoning <code>mondate</code>'s
 approach of representing days as fractional months.
 See examples.

Keep track of dates in terms of fractional calendar months
per Damien Laker "Time Calculations for Annualizing Returns: the Need for Standardization",
The Journal of Performance Measurement, 2008.
Model dates as of close of business.
Perform date arithmetic in units of "months" and "years".
Allow "infinite" dates to model "ultimate" time.

Dan Murphy

mondate

Keep Track of Dates in Terms of Months

subtract function

<dl><dt>e1</dt>
<dd>a <code>mondate</code></dd><dt>e2</dt>
<dd>a<code>numeric</code></dd><dt>units</dt>
<dd>Anything allowed by <code>base:::as.difftime</code>.
 In addition, can be "months" or "years".
 If missing, defaults to <code>timeunits(e1)</code>.</dd><dt>forcelastday</dt>
<dd>If FALSE, the result will have the same day of the month subject to
 the numbere of days in the month.
 If TRUE, the day of the month of the result will be the last day of the
 month if <code>e1</code> is on the last day of the month.</dd></dl>

Arguments

Author

Subtract numerics from mondates using day-of-month logic — subtract

<dl>

<dt>e1</dt>
<dd>a <code>mondate</code></dd>

<dt>e2</dt>
<dd>a<code>numeric</code></dd>

<dt>units</dt>
<dd>Anything allowed by <code>base:::as.difftime</code>.
 In addition, can be "months" or "years".
 If missing, defaults to <code>timeunits(e1)</code>.</dd>

<dt>forcelastday</dt>
<dd>If FALSE, the result will have the same day of the month subject to
 the numbere of days in the month.
 If TRUE, the day of the month of the result will be the last day of the
 month if <code>e1</code> is on the last day of the month.</dd>

</dl>

subtract: Subtract numerics from mondates using day-of-month logic

Description

Usage

Value

Arguments

Author

Examples