static time_t daysElapsed(const struct tm *now, const struct tm *last)
{
    const time_t diff = mktimeFromDateOnly(now) - mktimeFromDateOnly(last);
    return diff / (24 * 3600);
}
static time_t daysElapsed(const struct tm *now, const struct tm *last)
{
    const time_t diff = mktimeFromDateOnly(now) - mktimeFromDateOnly(last);
    return diff / (24 * 3600);
}