Often in genealogies you will encounter a double date, such as above, 20 January 1708-9, or written 1708/09. This is because the date so appeared in the original record where, according to the practice of that time, it was correctly given. No double-date appears in any year after March 25.
New Style dating began in 1752. Prior to that, the legal year was considered to begin with March 25th, though the historical year began as now. The system of double-dating was devised to cover both cases.
Using the instance above, the preceding month was December 1708, and the third month after was April 1709, and therefore, the true date, above, would be January 15, 1709. The double dates are used in genealogy works such as we study, to avoid confusion. If either of the two dates are dropped, it should be the first.
Certain cities and towns that are printing their early records are following the plan of dropping, not the first, but the second year, and the result is absurd. Suppose a man drew his will December 15, 1725, and died January 15, 1725/26. If you drop the last year here and print the date January 15, 1725, then the amazing assertion is made that the deceased signed his will eleven months after he died.