Final answer:
1:30am in international time is written as 01:30.
Step-by-step explanation:
To write 1:30am in international time, which is also known as the 24-hour clock format, you simply convert the time from the 12-hour format to a 24-hour format by adding 12 to the PM hours. However, since 1:30am is in the AM, we don't add anything and just write the time as it is but without the AM postfix. Therefore, 1:30am in international time is written as 01:30.