gap.py

#!/usr/bin/env python
import sys
import datetime

first = None
largest_gap = datetime.timedelta(0)
start = None
end  = None

for l in sys.stdin:
    second = datetime.datetime.fromisoformat(l.strip())

    if first:
        gap = second - first
        if gap > largest_gap:
            start = first
            end = second
            largest_gap = gap

    first = second

print(f"{start} | {end} | {largest_gap}")