#!/usr/bin/python3

# Converts Unix Timestamp to HKT

import sys
import datetime

def safe_cast(string):
    try:
        return int(string)
    except ValueError:
        print(f'Error: "{string}" is not a valid integer!')
        sys.exit()

# Check for user input
if len(sys.argv) < 2:
    print('Usage: convert-unixts <Timestamp: int>')
    sys.exit()

# Check for timestamp format 
raw_input = sys.argv[1]
if len(raw_input) < 10:
    print('Invalid timestamp format! Less than 10 digits.')
    sys.exit()
else:
    timestamp = safe_cast(raw_input)

# Convert to UTC
utc_time = datetime.datetime.utcfromtimestamp(timestamp)

# Convert to HKT (UTC+8)
hkt_time = utc_time + datetime.timedelta(hours=8)

# Print the result
print("HKT:", hkt_time.strftime('%Y-%m-%d %H:%M:%S'))