APIShed

• datemath_add — Adds years/months/days to date. years/months are applied together with end-of-month clamping — e.g. 2026-01-31 + 1 month = 2026-02-28, not an overflowed 2026-03
• datemath_age — Age in whole years as of asOf (optional, defaults to the current UTC date). A Feb-29 birthDate is treated as falling on March 1 in a non-leap asOf year.
• datemath_businessdays — Counts days in [from, to] (inclusive on both ends) whose weekday is in weekdays (default mon-fri) and which aren't in holidays.
• datemath_dayofweek — Day of the week for date: both the weekday name and its ISO 8601 weekday number (1=Monday..7=Sunday).
• datemath_diff — Day difference between two YYYY-MM-DD dates: to minus from, in whole days. Negative if to is before from.
• datemath_leapyear — Checks whether year is a leap year in the Gregorian calendar.
• ean_validate — Validates an 8-digit (EAN-8), 12-digit (UPC-A), 13-digit (EAN-13), or 14-digit (GTIN-14) barcode checksum: alternating weights 1 3 applied right-to-left, check
• email_validate — Checks value is a single, bare RFC 5322 email address — syntax only, not a deliverability check. user@localhost is valid (no TLD required). "Name <email>" displ
• hash_digest — Computes a hash digest of input (decoded per encoding: "text" default, "base64", or "hex") using algo: md5, sha1, sha256, sha512, or crc32. Returns the digest a
• iban_validate — Validates an IBAN's length for its issuing country (per the SWIFT IBAN registry) and its mod-97 checksum. Does not decompose the BBAN into a bank code/account n
• isbn_validate — Validates a 10- or 13-character ISBN. ISBN-10 uses weights 10..1 over 10 characters (last may be X, worth 10), sum mod 11 must be 0. ISBN-13 uses the same GTIN
• jsonschema_validate — Validates document against schema (JSON Schema draft-07 or 2020-12). Reports one specific violation per call, not an aggregated list.
• luhn_validate — Validates a numeric string against the Luhn (mod-10) checksum — payment card numbers, IMEI numbers, and similar identifiers.

No long description beyond the summary.