Chronology of events: 1246--1631
For some events, the year is certain but the month and day are not. Example: We know only the year for the collections of Leeuwenhoek's letters published in Dutch during his lifetime.
For other events, the season or month are certain but the day is not. Example: Leeuwenhoek mentions that someone visited him "last month".
On the other hand, many events did indeed happen on the first day of a month. Example: public appointments to Delft's city offices took effect on January 1 of each year. Thus:
- A date of January 1 in a given year may indicate that the year is certain but the month and day are not.
- A date of 1 in a given month may indicate that the year and month are certain but the day is not.
Unless otherwise indicated, for events in England, the date given is Old Style, 10 days behind the Dutch Republic's New Style until 1700 and then 11 days behind.