__attribute__((format (printf,2,0)))
extern void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap);
+/**
+ * Add the time specified by `tm`, as formatted by `strftime`.
+ */
+extern void strbuf_addftime(struct strbuf *sb, const char *fmt, const struct tm *tm);
+
/**
* Read a given size of data from a FILE* pointer to the buffer.
*