I want to know the exact time for throwing the pebbles (rami al-jamarat), its beginning and end.

Throwing the pebbles at Jamrat al-Aqaba begins on the day of Eid for those who are able, from sunrise until sunset. For the weak, the elderly, and women, it is permissible to throw the pebbles from the last part of the night. It is not permissible to delay the throwing until the dawn of the eleventh day.

As for throwing the pebbles at the Jamarat (definition) during the Days of Tashreeq (11th, 12th, and 13th of Dhul-Hijjah), it begins from the decline of the sun (the beginning of Dhuhr prayer time) and continues into the night. It is not permissible to throw the pebbles before the decline of the sun, following the action of the Prophet, peace and blessings be upon him. If difficulty arises due to overcrowding, it is permissible to throw the pebbles at night until dawn, with preference given to throwing them during the day if there is no necessity or difficulty.