Date Rule Grammar
Introduction
Date rules are used in OpenDataDSL to calculate dates instead of using fixed dates.
The Grammar
The grammar is provided in the form of a string representing a date calculation with relative and absolute changes from a reference date point.
Syntax
The syntax is as follows:
T[+/-][relative][absolute]
Relative syntax
The relative component of the syntax is as follows:
[nY]{nQ][nM][nW][nD][nh][nm][ns]
Absolute syntax
The absolute component of the syntax is as follows:
[Ynnnn][Qn][Mnn][Wnn][Dnn][hnn][mnn][snn]
Reference date
The reference date is the point from which the rules start calculating. This is usually now unless the dates are in relation to a curve, report or matrix, then it is the ondate.
Period qualifiers
The periods in the grammar are defined as:
- Y - Year
- Q - Quarter
- M - Month
- W - Week
- D - Day
- h - Hour
- m - Minute
- s - Second
Relative parts
The relative parts always start with a number which represents the number of periods and then a period qualifier. E.g. T-1Y2M means subtract 1 year and 2 months from the reference date
Absolute parts
The absolute parts always start with a period qualifier and then a number representing the absolute period. E.g. T-M1D1h0m0s0 means the start of the day on the 1st of January of the current year
Examples
Using a reference date/time of 8th July 2024 at 16:23:07 - 2024-07-08T16:23:07
| Code | Calculated Date/time |
|---|---|
| T-1Y | 2023-07-08T16:23:07 |
| T-1Yh0m0s0 | 2023-07-08T00:00:00 |
| T-M1D1h0m0s0 | 2024-01-01T00:00:00 |
| T-5D | 2024-07-03T16:23:07 |
| T+5D | 2024-07-13T16:23:07 |
| T-1YQ4D1h0m0s0 | 2023-10-01T00:00:00 |