The proposed Transbay Tower, which you should know is going to be very tall and very adjacent to the rebuilt Transbay Terminal and it's 5.4 acre park, has hit another road bump on its way to becoming the tallest building west of the Mississippi. According to some folks from the anti-shady-areas contingent, the tower could cast a long shadow from SoMa all the way to North Beach.
There are ways to model these kind of heliological situations and the city says tower opponents are exaggerating claims that the building will black out 90% of Portsmouth Square and 100% of Union Square, pointing out that those scenarios only exist for a tiny portion of the day and operate on the assumption that the Transbay Tower is shaped like a giant refrigerator. Meanwhile, opponents like Bill Maher (not that Bill Maher) claim the tower will "eliminate a significant amount of public sunlight that the public can never get back." The same public sunlight that is constantly changing and after a few minutes won't really be back in the same place for an entire year anyway.
Of course, we would never wish anyone spend their whole year in the shadows. (Personally, we like to walk on the sunny side of the street on chilly days and on the shady side of the street in sunny days. It helps regulate one's internal temperature.) But since we've got the city planners, SPUR and opponents all doing these sunlight studies maybe we can have them whip up our very own Manhattenhenge phenomenon. Surely that would please everyone at least once a year?