From Ilford's sheet
The table of development times given here gives an appropriate starting point
From Kodak's
The development times in the following tables are starting-point recommendation; for critical applications, run tests to determine the best development time. If your films are consistently too low in contrast, increase the development time slightly (10 to 15 percent); if they are too contrasty, decrease the development time slightly (10 to 15 percent).
For traditional B&W films, in a general sense, there isn't a development time that is "the right answer", "the perfect answer", or "the only answer" instead; from any outside source ( Kodak, Ilford, me), one gets "suggested times".
Suggested times are generally "plenty close enough" because you should be able to get a printable negative with most any suggestion.
The printing adjustment that is required for most of us to "fix" a film development time "error", is changing the paper grade by changing the filters in the enlarger. This contrast adjustment for the paper is a step/an adjustment that is at minimum normal, but more generally required to get good results because each scene is different, the film development is just one of the variables.