Time.DateTime.rfc3339: def of bend-kit-time@0.3.0.0
Import: import bend-kit-time@0.3.0.0/time.bend as Time
Lines 342-346 of bend-kit-time@0.3.0.0/time.bend: https://jend.leeeet.dev/read.txt?path=bend-kit-time@0.3.0.0/time.bend&start_line=342&end_line=346

import Base

def DateTime.rfc3339(t: DateTime) -> String:
  match t:
    case DateTime{Date{y, mo, d}, h, mi, s, n}:
      String.concat([pad(y, 4n), "-", pad(mo, 2n), "-", pad(d, 2n), "T", pad(h, 2n), ":",
        pad(mi, 2n), ":", pad(s, 2n), frac(n), "Z"])

Uses (7):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String.concat
  https://jend.leeeet.dev/definition.txt?path=bend-kit-time@0.3.0.0/time.bend&name=Date
  https://jend.leeeet.dev/definition.txt?path=bend-kit-time@0.3.0.0/time.bend&name=DateTime
  https://jend.leeeet.dev/definition.txt?path=bend-kit-time@0.3.0.0/time.bend&name=frac
  https://jend.leeeet.dev/definition.txt?path=bend-kit-time@0.3.0.0/time.bend&name=pad