Using Date Aliases and Date Options

This chapter provides overviews of date aliases and options, and raw and decimal dates, and discusses how to:

• Use date aliases.

• Use dates in pension calculations.

Understanding Date Aliases and Options

Dates are elemental to pension calculations. The date of birth, date of hire, normal and early retirement dates, and benefit commencement date are just some of the important dates you use.

Dates stored in the database are accessible using database aliases. Many other dates, however, are derived rather than stored. For example, normal retirement date may be the participant’s 65th birthday or the first of the month following that birthday.

Date aliases enable you to derive dates using your plan’s date math and rounding rules. Date aliases support a number of different types of date manipulations.

Understanding Raw and Decimal Dates

You can work with dates in either raw or decimal formats.

The raw date format expresses a date in years, months, and days, as in December 15, 2003. The format of a date can change (for example, when you perform certain date math, you use the format yyyy/mm/dd); regardless, any date expressed in terms of years, months, and days is a raw date.

The decimal date format represents a raw date in years-only format. The months and days are converted to partial years. For example, July 1, 2002, can be expressed as 2002.5000. You might convert dates to a decimal format to simplify date subtraction and thus determine the length of time between two dates.

Unless you specifically convert a date to the decimal format using the date conversion option, you can assume that the dates you deal with are raw dates.

Using Date Aliases

Date aliases calculate dates by:

• Adding a period of time to one date to calculate another.

• Applying date rounding options.

• Applying date conversion options.

• Finding the date associated with a specific amount of service accrual.

You can only perform one operation per definition. Any combination of actions requires multiple date definitions. For example, to find the first of the month after an employee reaches age 21, set up one date alias to add 21 years to the employee’s date of birth, and set up a second date alias to round that value to the first of the following month.

Using Dates in Pension Calculations

To use dates in pension calculations, use the Date Alias (DATES), Date Round (DATE_ROUNDING_OPTI), and Date Conversion (DATE_CONVERSIONS) components.

This section lists the pages used to use dates in pension calculations and discusses how to:

• Manipulate dates.

• Set the date round option.

• Convert dates.

• Review sample conversions.

Pages Used to Use Dates in Pension Calculations

Manipulating Dates

Access the Date Alias page.

Date-From

Date Option

Select the type of manipulation you want to perform. You can add time to a date, determine a service date, or convert or round a date. The fields that are available for entry depend on your selection.

Add Time to Date

Service

A date alias can look up the date when an employee attains a specified amount of service. For example, to set up an alias for the date of first vesting, you could look for the date when an employee will have accrued five years of vesting service.

The function result provides all the information needed to calculate the date, including a projection method for future service.

The system does not necessarily determine the exact day that an employee attains the specified amount of service. Instead, the system looks at the service history, finds the period when the employee attained the specified service amount, then uses the first day of the next period. How exact this date is depends on how you set up your service requirement. Monthly service accrual methods provide more precise values than yearly service accrual methods.

Note. Service dates are not necessarily exact.

Options

Setting the Date Round Option

Pension plans frequently round dates. For example, if normal retirement date (NRD) is the first of the month after a participant's 65th birthday, you create an NRD alias by applying a rounding option to the date representing the birthday.

Access the Date Round Option page.

Date Type

Rounding Rule

A rounding rule consists of three parts, as shown in the following examples:

When you round to the last day of a period, you do not have to specify the rounding rule. In this case, the date is always rounded to the last day of the current period. For example, if you round to the last day of the calendar month, August 8, 2008 becomes August 31, 2008. If, however, you round to the first day of a period, you must select a rounding rule.

There are also two options that round based on a threshold that you specify:

• Up if Day/Month => Threshold No.

• Up if Day/Month => Threshold No. … Else Down

With both of these options, you specify the threshold number of days in a month (if the rounding period is months) or months in a year (if the rounding period is any type of year). Both options round up after the specified number of days or months. However, the first option leaves dates under the threshold unrounded, whereas the second option rounds down.

Note. The threshold options do not apply if you round decimal dates.

The following tables illustrate how each of these options works. In all cases, we are rounding to the first of the month.

Converting Dates

Access the Date Conversion Option page.

Option Type

Assumptions

Extract

Sometimes a calculation needs the year, month, or day of a date, but not all three. For example, suppose your employees’ periodic earnings consolidations are based on compensation rate on each anniversary of their hire dates. You need date aliases that determine the month and the day of hire. This means that if an employee is hired on March 17, 2007, the month extraction alias resolves to 3, and the day extraction alias resolves to 17.

Conversion Method

When you convert raw dates to decimal dates, you have to convert months and days to partial years. There are a number of ways to do this, depending on your assumptions and your conversion method.

To understand the differences among the options, walk through some sample conversions.

Notice that the conversion methods use Months - 1 and Days - 1. They use this method in order to work with whole months and days. For example, June 6, 2002 is only six days into in the sixth month, June; and the last whole month is the fifth month, May.

Reviewing Sample Conversions

This topic uses each method to convert a raw date, June 6, 2002, to a decimal date. Assume there are 30 days per month, 365 days per year, and four decimal places.

Years + (( Months - 1) * (Days/Month)) + Days - 1) / (Days/Year)

This example converts the raw date June 6, 2002 to a decimal date.

Years + (whole months converted to days + whole days) converted 
to partial years
Years = 2002
Whole months converted to days = (6 - 1) * 30 = 5 * 30 = 150
Whole days = 6 - 1 =5
Total days = (150 + 5) = 155 
Total days converted to partial years = 155 / 365 = .4247

Years + ( Months - 1) / 12 + (Days - 1) / ( Days/Year)

This example converts the raw date June 6, 2002 to a decimal date.

Years + whole months converted to partial years + whole days 
converted to partial years

Years = 2002
Whole months converted to partial years  = (6-1) / 12 = 5 / 12 = .4167
Whole days converted to partial years = (6-1) / 365 = 5 / 365 = .0137

Result: 2002.4304

Date Tables: Years + (Actual Days - 1)

To find the (actual days - 1) value of June 6, 2002, add 31 (January), 29 (February in a leap year), 31 (March), 30 (April), 31 (May), and 5 (June through yesterday) for a final value of 157. This is converted to years using the actual number of days in this year: 366 because of the leap year.

Years + actual days converted to partial years
Years = 2002
Actual days converted to partial years = 157 / 366 = .4290
Result: 2002.4290