Trivial curiosity questions:  What day is it? (Does the Socratic date change based on the change at the international date line? It often seems to be one date later on Socratic than it is where I live.).
All dates and times on Socratic are based on the UTC timezone. Click here to see the current time in UTC.
UTC , aka "Coordinated Universal Time", is a timezone based at 0
Storing time in databases can get complicated since there are so many options for formats and timezones.
To avoid ambiguity and complexity, we store all times as UNIX timestamps, which counts the number of seconds in the UTC timezone since 00:00:00 on 1 January 1970.
I'm writing this answer at 10:51am in EDT timezone (New York), which is 2:51pm in UTC, but both are at the timestamp 1438699916.
All statistics are calculated based on UTC days.
Whenever possible, we show the time "from now" for an event, instead of the actual UTC time the event happened. E.g., we'll say a question was answered "5 minutes ago", instead of showing the UTC time, since "5 minutes ago" will be true for all readers, and easy to understand.