Hay, yan ang frustrating talaga! Hives na umuulit lang sa specific times of day usually may trigger, either something sa environment na bumabago (like heat, sweat, or dust from daily activities), or something sa food/drinks na kinakain mo around that time. Mas maganda talagang i-check mo with a doctor kasi pwede ring related sa allergies or skin condition na need ng proper diagnosis, lalo na kung paulit-ulit na. In the meantime, try mo mag-note ng what you're wearing, eating, at ano ang ginagawa mo bago mag-appear ang hives, super helpful yan for the doc!