At night time
Every night before going to sleep the two may talk for a while.
Both of you plan your work for the next day. Only then you have to spend time figuring out when there is any break for both of you.
Waking up quickly
Both do not wake up at the same time every morning. We rise according to their works.
But if you want to spend time between the two of you, wake up a little earlier than usual in the morning.
Both of you can take some time for yourself before starting your regular work.
Find the time
Try to share your time with each other even during working hours during the day.
If both their offices are next to each other, they can meet at lunch time. You can go to a nearby restaurant to eat. If you are far away and you cannot meet in person, you can be in touch by phone or medium at that time.