DATEFMT

Key Characteristics

• • Contextual Usage: Most commonly specified within SORT or MERGE control statements for DFSORT and ICETOOL, or as a parameter to other date-sensitive utilities.
  • Format Specification: Allows users to define the exact layout of a date field, such as YYYYMMDD, MMDDYYYY, DDMMYYYY, YYMMDD, MMDDYY, DDMMYY, and variations including separators (e.g., YYYY/MM/DD).
  • Data Type Agnostic: Can be applied to date fields stored as character, packed decimal, or zoned decimal data, provided the format string accurately describes the field's content.
  • Century Handling: Supports both 2-digit and 4-digit year formats, often with implicit or explicit century windowing for 2-digit years to correctly interpret dates across centuries (e.g., YY vs. YYYY).
  • Impact on Operations: Directly influences the logical comparison and ordering of records based on date fields, crucial for accurate sorting, merging, and selection.

Use Cases

• • Sorting Data by Date: Ordering transaction records chronologically, regardless of the physical storage format of the date field, using DFSORT or ICETOOL.
  • Date Field Conversion/Reformatting: Changing the representation of a date field from one format to another (e.g., MMDDYY to YYYYMMDD) for reporting or interface requirements.
  • Selecting Records Based on Date Ranges: Filtering data to include only records within a specific date range, where DATEFMT ensures correct comparison logic.
  • Merging Datasets: Combining multiple datasets that contain date fields, ensuring that the merge operation correctly orders records from different sources based on their dates.
  • Generating Reports: Presenting dates in a user-friendly or standardized format in output reports, often after processing with a utility that uses DATEFMT.

Related Concepts