Fix reference to epoch in the tutorial

Author: waveform80

docs/tutorial_basic.rst

@@ -431,10 +431,10 @@ Date Handling
 -------------
 
 The other important switches are those used in the detection of dates encoded
-as numbers: :option:`structa --min-timestamp` and :option:`structa
---max-timestamp`. When dates are encoded as (potentially fractional)
-day-offsets from some :option:`structa --epoch` (which defaults to the UNIX
-epoch, i.e. the 1st January, 1970), how does structa determine that it's
+as numbers: :option:`structa --min-timestamp`, :option:`structa
+--max-timestamp`, and :option:`structa --timestamps`. When dates are encoded as
+(potentially fractional) day-offsets from some epoch (which defaults to the
+UNIX epoch, i.e. the 1st January, 1970), how does structa determine that it's
 looking at a set of dates rather than a set of numbers?
 
 In a typical set of (arbitrary) numbers, it's quite normal to find "0" or "1"