@11ty/parse-date-strings

Eleventy’s ISO8601 Date parser

Features:

• Zero dependency super minimal ISO8601 date parsing library. Alternatives were too lax, inaccurate, huge on disk, or huge in bundle.
• Dates with 8 digits do not require - delimiters (all other dates require delimiters, e.g. YYYY-MM)
• Times with 6 digits do not require : delimiters (all others times require delimiters, e.g. HH:II)
• Requires the T delimiter for date and time
• Defaults to UTC when time zone is unknown instead of local time (Z can be explicit or implied)
  • This matches previous behavior in Eleventy and this feature maintains consistency between build and deploy servers.
• Supports +00:00 or -00:00 style time zone offsets
• Invalid strings throw errors.

Not supported:

• Standalone times are not supported (must be date or datetime)
• ISO week date syntax (e.g. YYYY-W01-1)
• Day of year syntax is not supported (e.g. YYYY-001, YYYY-365)
• Fractional syntax for hours or minutes (e.g. T14.6 or T10:30.6). Fractional seconds (e.g. milliseconds) are supported (of course).

luxon Comparison

More strict parsing compared with Luxon’s fromISO (used in Eleventy v0.x through v3):

2016
2016-05
201605                    # Dropped, delimiter required if date is not 8 digits
2016-05-25
20160525
2016-05-25T09
2016-05-25T09:24
2016-05-25T09:24:15
2016-05-25T09:24:15.123
2016-05-25T0924
2016-05-25T092415
2016-05-25T092415.123
2016-05-25T09:24:15,123

# No ISO week date syntax
2016-W21-3                # Dropped
2016W213                  # Dropped
2016-W21-3T09:24:15.123   # Dropped
2016W213T09:24:15.123     # Dropped

# No day of year syntax (e.g. 200th day of the year)
2016-200                  # Dropped
2016200                   # Dropped
2016-200T09:24:15.123     # Dropped

# No implied current day (time-only syntax)
09:24                     # Dropped
09:24:15                  # Dropped
09:24:15.123              # Dropped
09:24:15,123              # Dropped