Eek. I think I take the opposing view. Your calendar is your business. What right do I have to see yours?
Company and union are entities. Company is your employer. Union is your representation agent. The average John Doe pilot on the like is nothing - from your schedule perspective.
I think it’s a privacy thing. At our shop, I’m not aware of any “live” system to see someone else’s schedule. There is a buddy system, but you’d have to add their EMP # as a buddy for the buddies to see each others schedules.
Your schedule - your business
I believe that the 30,000 ft overview of this is ensuring ther integrity of whatever your scheduling system is. Seeing a "calendar" is just one way of protecting overall schedule integrity.
Trips/Pairings/Rotations - they aren't lines of flying. They are "commodities." As soon as we turned flying into a expiring resource of different values, we created a secondary market - and that market needs oversight. The best oversight is always transparency.
I'll talk about the two extremes... 1.) The reserve pilot that doesn't want to fly. 2.) The hustler that wants to pad their schedule with cushy and productive trips to 300 hrs/month.
1.) Whatever your reserve system is - there needs to be transparency in it so that you have a clear view of where you are on the "assignment board" so that when you are called you can say with certainty that the trip that you were assigned was built legally, in a timely manner, and was assigned to the proper pilot. (i.e. you) Reserve is a tradeoff where you are going to get more time "at home" in exchange for some (as my MIL bros/sis's would say...) BOHICA. If you are paying a little attention - 95% of assignments shouldn't come as a surprise.
2.) Hustlers... A lot of this is the same... it's all about the integrity of assignments. And seeing a "calendar" is just one way of verification - another would be being able to see information about the trip as to when the leg/trip/pairing/rotation became open - when it was built/rebuilt - when it "hit" open time - who tried to pick it up, who was denied, awarded, etc.
The reason I talk about integrity is because in many cases we are talking about not only contractual issues where your bargaining agent cannot "take sides" between one pilot and another, but we are talking about real amounts of money and quality of life issues. Being able to swap/pickup/drop a trip can mean the difference in thousands of dollars in ones paycheck and time away or at home. It can be something as simple as an overnight at the all-inclusive beach vs. a snow covered wasteland with no food for miles.
There needs to be a way for whatever system you have to be audited by the members. No one has the time or the energy to oversee the overall integrity of hundreds or thousands of transactions... but "random" audits by members who want to know why it didn't work out in their favor - that's what keeps the system honest.
The hustler pilot only cares that their daily fix was taken care of, the are already on to the next "high." - the reserve just doesn't want to be used and get paid for sitting at home. The 90% inbetween want to know why... why the couple of times a month they try to use the tools that exist to improve their schedule aren't working. And why things always seem to work out for pilot X, Y, and Z.
Once computers entered the arena and "how fast you (or the AI) push the button" became a thing the system changed. The opportunities to slew the playing field out of level necessitates more transparency, whatever your system.