given:
20230607013934

-04 hours (because my computer is EDT?)

output:
202306062139.34


2023 06 07 01 39 34

2023-06-07 01:39:34
2023-06-07 01:39:34-0400

# 20230607013934
GIVEN=20230607013934
GIVEN_DATE=$(echo $GIVEN | sed 's/\(....\)\(..\)\(..\)\(..\)\(..\)\(..\)/\1-\2-\3 \4:\5:\6/')
# 2023-06-07 01:39:34
UTC="$(date -d "$GIVEN_DATE"Z +%Y%m%d%H%M.%S)"