What can I do to pass time while waiting for a big event?

Read a novel or two (or more) that take place in you destination,

Binge watch YouTube.

Clean your apartment/house spic and span.

Plan and make an extensive list down to the details of what you’re bringing and what clothes you’re taking. Get them ready – wash, dry, iron, dry-clean, purchase some, whatever.

Make a list of everything you need to do before you go and do those things – pay bills, transfer funds, put a hold on the newspaper or mail.

Make sure your laptop/tablet is functioning properly and has whatever you may need loaded into it – books, photos, plenty of storage space, etc.

Make an itinerary to leave with a trusted friend or relative so someone will know where you are and how to get in touch.

Not only are these things productive, they’ll be part of the trip itself. A journey isn’t simply when you get there, it’s also about the excitement of getting there!

Do a practice run on packing your bags. Make sure you have everything you need/want and that you know where it is. Make a list and check it twice.

Once you have that in place and know you are “ready” for the trip without having to worry about last minute crises popping up, go about your normal life. You could do a little research on where you are going to see if there are any special things you can do while you are there.

Well, one thing I do is to fix on another nearby date and attach some connection to it, and especially a date that tends to come too soon; for example, “By the time I have my next dental check, my trip will be only a week away.” or “No rush. Property tax is due right after I get back.”

I also totally agree with thorough and well-conceived packing lists. I take my list with me and mark it up as I go—didn’t need two of those; bring an extra of that—and use it as a starter for my next trip.

43 days is quite sometime.
I am the opposite. I book it, schedule the dog boarding, put a reminder in my phone and forget about it till 2 days prior. I pack lite the hour before I leave. I think I have 2 trips in the queue within the next few months.
Try that!
Serious however you can think of some fun extras to do on your trip to make it Uber memorable. (Sightseeing, food outings, concerts or events in the area when you are there, spa day)
Research the area and read some books set in the location.
Enjoy!!!

Try to learn as much as you can about the area. If it is a foreign country you can study and learn a little of the language?
Are there any geocaches hidden in the area? Plan on finding a few. You will blow your friends’ minds when you are walking on the street and reach into the crotch of a tree and pull out a small box. They will think you are a genius!
If you’ve never done it, practice finding some geocaches in your neighborhood.
Geocaching:https://www.geocaching.com/play