[Bug] RTC convert_timestamp offset issue for month

[adaminato42]

Describe the Bug

The string offset for checking the month in convert_timestamp is looking at the 2nd character of the month, instead of the 3rd, for both A and M:

qmk_modules/rtc/rtc.c

Lines 160 to 174 in 218388e

	rtc_time_t convert_timestamp(const char *timestamp) {
	rtc_time_t t;
	// Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
	switch (timestamp[4]) {
	case 'J':
	t.month = (timestamp[5] == 'a') ? 1 : ((timestamp[6] == 'n') ? 6 : 7);
	break;
	case 'F':
	t.month = 2;
	break;
	case 'A':
	t.month = timestamp[5] == 'r' ? 4 : 8;
	break;
	case 'M':
	t.month = timestamp[5] == 'r' ? 3 : 5;

This results in incorrect values being returned for Mar or Apr

Can the offset be changed to address this? Alternatively, perhaps helper to parse the month?

// Helper function to parse month abbreviation (e.g. "Jan", "Feb", ...)
static uint8_t parse_month(const char *str) {
    static const char *months[] = {
        "Jan", "Feb", "Mar", "Apr", "May", "Jun",
        "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
    };
    for (uint8_t i = 0; i < 12; ++i) {
        if (strncmp(str, months[i], 3) == 0) {
            return i + 1;
        }
    }
    return 0; // Invalid month
}

// Replace the switch block with:
t.month = parse_month(&timestamp[4]);

Additional Context?

No response

[drashna]

A should be fine for this, as the 2nd letter should be p or u (for april and augist, respectively). But yeah, for May and March, it's incorrect.

This should be fixed in: fc260ba