+# The extglob shell option must be enabled to use the pattern generated by this
+# function (shopt -s extglob/ shopt -u extglob).
+# The pattern returned by this function is to validate the form:
+# YYYYMMDDTHHMMSS[+-]HHMM-YYYYMMDDTHHMMSS[+-]HHMM
+#
+# Where YYYYMMDD is today or tomorrow. Tomorrow must be supported in case where
+# the chunks are generated close to midnight and one ends up the following day.
+function get_chunk_pattern ()