DateTimeCalculator
Performs arithmetic on date, time, datetime, and interval values. In Advanced Expression mode, composite expressions involving datetimes and intervals may be constructed.
See also: Date/Time Terminology, Date/Time Format, Date/Time Functions
The DateTimeCalculator performs arithmetic on five temporal types:
 Date
 Time
 Time with UTC offset
 Datetime
 Datetime with UTC offset
The input temporal strings must be in FME format or ISO 8601 format.
DateTimeCalculator also supports interval arithmetic, where the interval can be specified in one of two ways:
 Specified by part. For example, the user can specify 5 for the value of “Years”.
 Specified by an interval string in ISO 8601 duration format.
Invalid temporal and interval input will cause date time functions that consume them to return null, and cause the feature to be rejected.
Limitations:
 Supported temporal range: 00010101 00:00:00.000000000 to 99991231 23:59:59.999999999.
 If the input temporal value contains fractional seconds, only the decimal separator “.” is supported.
 When subtracting a temporal value from another, the two temporal values must have compatible temporal types, or the feature will be rejected. Please see the type compatibility matrix.
 If an interval is specified by parts, then the part values must be either all nonnegative, or all nonpositive, or the feature will be rejected.
Input Ports
Accepts and processes features one by one. Temporal values and interval values can come from attributes.
Output Ports
Outputs valid results.
Outputs invalid results, which are set to null. When features come out of this port, please check if the input strings are valid syntactically, and then if they are valid semantically.
Note: Feature order may change in relation to other output ports. Feature order per port is maintained.
Parameters
Specifies the operation to perform:
 Add or Subtract Interval: add an interval to or subtract it from a temporal value. The interval is specified by part. That is, by years, months, days, hours, minutes, and fractional seconds. Only seconds are allowed to be fractional. The other parts are integers. The parts must be all nonnegative or all nonpositive, otherwise the feature is rejected. The result has the same temporal type as the input temporal type.
 Add or Subtract Interval (ISO Duration): add an interval to or subtract it from a temporal value. The interval is specified in ISO 8601 duration format. The result has the same temporal type as the input temporal type.
 Calculate Interval between Datetimes: end time minus start time produces an interval. The user can choose to output the interval in ISO 8601 duration format, or as fractional years, months, weeks, days, hours, minutes, or seconds.
 Advanced Expression: datetime functions can be used to construct composite expressions such as @DateTimeAdd(time1, @DateTimeDiff(@Value(time2) – @Value(time3)).
Specify a starting temporal value. Choose whether to add or subtract an interval. Then, specify values for the interval parts of interest. The interval parts supported are years, months, days, hours, minutes, and seconds. The seconds parameter can be fractional. The other part values must be integers.
Note: Float values for integeronly fields are rounded into integers.
Specify a starting temporal value. Choose whether to add or subtract an interval. Then, specify the interval with ISO 8601 duration format.
Specify start and end temporal values. Then, pick the output interval type. Supported interval types are:
 ISO 8601 duration format.
 Fractional years, which is calculated as the number of fractional months divided by 12.
 Fractional months: between a start and an end datetime there are a number of full months. The remainder that is not a full month consists of a number of days, hours, minutes, and seconds. The remainder starts in a month that is referred to as a "remainder month". The remainder is first converted into fractional days. Then, the fractional days are divided by the number of days in a remainder month. The remainder month is the month just preceding (and containing a part or all of) the remainder, and guarantees that the remainder is never greater than a month, when expressed as a fractional month. Finally, the remainder as a fractional month is added to the number of full months, to give us the resulting fractional months.
 Example, from 2016Jan01 (start) to 2017Mar31 (end) there is 1 year and 2 months plus a remainder. 2016Jan01 + 1 year + 2 months takes us to 2017Mar01, which means that the remainder month is 2017Mar. That month has 31 days. So, the remainder of 30 days, is divided by 31 to get the fractional month. The total number of months between the two dates are therefore 1 year (12 months) + 2 months + 30/31 months = 14.967742.
 Weeks, days, hours, minutes, seconds: for all of these, we first compute the duration between a start and an end datetime in fractional seconds. Conversion then occurs to the specified unit. There are 60 seconds in a minute. 60 minutes in an hour, 24 hours in a day, and 7 days in a week.
Note: To reuse fractional years, months, weeks, days, hours, or minutes in a DateTimeCalculator or @DateTimeAdd(), please round or truncate the fractional values into integers first.
Tip: Fractional years, months, weeks, days, hours, minutes, or seconds as the output interval type may be useful for comparison and reporting.
Construct composite FME expressions involving datetime, for example:
 @DateTimeAdd(@Value(newStartDate),@DateTimeDiff(@Value(projEnd),@Value(projStart))
 @DateTimeCast(@DateTimeNow(),time)
 @DateTimeFormat(@DateTimeParse(@Value(sourceString),@Value(inputFormat)),@Value(outputFormat))
Please see FME Date/Time Functions.
Editing Transformer Parameters
Using a set of menu options, transformer parameters can be assigned by referencing other elements in the workspace. More advanced functions, such as an advanced editor and an arithmetic editor, are also available in some transformers. To access a menu of these options, click beside the applicable parameter. For more information, see Transformer Parameter Menu Options.
Defining Values
There are several ways to define a value for use in a Transformer. The simplest is to simply type in a value or string, which can include functions of various types such as attribute references, math and string functions, and workspace parameters. There are a number of tools and shortcuts that can assist in constructing values, generally available from the dropdown context menu adjacent to the value field.
Using the Text Editor
The Text Editor provides a convenient way to construct text strings (including regular expressions) from various data sources, such as attributes, parameters, and constants, where the result is used directly inside a parameter.
Using the Arithmetic Editor
The Arithmetic Editor provides a convenient way to construct math expressions from various data sources, such as attributes, parameters, and feature functions, where the result is used directly inside a parameter.
Conditional Values
Set values depending on one or more test conditions that either pass or fail.
Parameter Condition Definition Dialog
Content
Expressions and strings can include a number of functions, characters, parameters, and more.
When setting values  whether entered directly in a parameter or constructed using one of the editors  strings and expressions containing String, Math, Date/Time or FME Feature Functions will have those functions evaluated. Therefore, the names of these functions (in the form @<function_name>) should not be used as literal string values.
These functions manipulate and format strings.  
Special Characters 
A set of control characters is available in the Text Editor. 
Math functions are available in both editors.  
Date/Time Functions  Date and time functions are available in the Text Editor. 
These operators are available in the Arithmetic Editor.  
These return primarily featurespecific values.  
FME and workspacespecific parameters may be used.  
Creating and Modifying User Parameters  Create your own editable parameters. 
Dialog Options  Tables
Transformers with tablestyle parameters have additional tools for populating and manipulating values.
Row Reordering

Enabled once you have clicked on a row item. Choices include:

Cut, Copy, and Paste

Enabled once you have clicked on a row item. Choices include:
Cut, copy, and paste may be used within a transformer, or between transformers. 
Filter

Start typing a string, and the matrix will only display rows matching those characters. Searches all columns. This only affects the display of attributes within the transformer  it does not alter which attributes are output. 
Import

Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers. 
Reset/Refresh

Generally resets the table to its initial state, and may provide additional options to remove invalid entries. Behavior varies between transformers. 
Note: Not all tools are available in all transformers.
FME Community
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