Time Zones

Ne idea y the concept of time zones was evolevd

i mean it makes sense and all but how did thew concept started or evolved..eg givin elecrons the + sign and proton the negative charge makes more sense but since we already had decided otherwise so we continued with the earlier system...then y the concept of time zones...i dont see the usefulness of timezones before the 20th century...so it must hv evolved recently...ne1 with some googling skills