I'm totally mind boggled that some put Sentry as the fastest when in reality he's the slowest.
No one can even name one of his best traveling feats.
For example, the DC universe is at least 200 trillion light years wide (there is a scan showing Superman being 100 trillion light years away from Earth) and possibly more than 1e20 light years wide if you consider the DC universe expanded to 60 trillion light years the first half second (astronomically more faster than ours) and calculate the rest using the current expansion rate theory.
Using the lowball 100 trillion light year estimate in 60 days then Superman traveled on average 19 million light years per second.
To put this in perspective, galaxies range starting from 3300 light years wide. The milky way (a large galaxy) is about 100,000 light years wide.
So Superman traveled a milky way galaxy distance in 5 milliseconds.