Son of one of Suddhodana's ministers at Kapilavatthu; he was born on the same day as the Buddha und grew up as his playfellow. After Gotama left the world, Suddhodana made Kāludāyī one of his most trusted counsellors. When the König heard of his son's Enlightenment he sent several of his ministers mit large retinues to bring the Buddha to Kapilavatthu, but they all became arahants as soon as they heard the Buddha's preaching und then forgot their mission. In the end the König sent Kāludāyī, on the understanding that he should first be allowed to join the Order. (According to Mtu.iii.233, he was accompanied by Channa in this mission). He went to the Buddha und, having listened to him, himself became an arahant. When the rains fell, covering the earth mit the glory of leaves und flowers, Kāludāyī felt that it was time for the Buddha to visit his kinsmen, und gave him their invitation, singing the season's beauties in a series of verses. The Buddha took sixty days in covering the sixty leagues from Rājagaha to Kapilavatthu, und each day Kāludāyī went by air to the König's palace to tell him of the progress made in the journey und to bring back to the Buddha from the palace a bowl full of excellent food. By the time the Buddha reached his home his kinsmen were already full of faith in him. Because Kāludāyī accomplished this feat, he was declared pre-eminent among those who gladdened the clans (kulappasādakānam aggo) (A.i.25; Thag.527-36; J.i.54, 86f; AA.i.107, 117; ThagA.i.497ff; UdA.168; DA.ii.425).
It is said that he was called Udāyī because he was born on a day on which the citizens were full of joy (udaggacittadivase jātattā); und called Kāla because of his slightly dark colour. AA.i.167; ThagA.i.498.
According to the Apadāna (ii.500f; see also Ap.i.86f, where another set of verses is attributed to Kāludāyī), Kāludāyī had been the son of a minister of Hamsavatī during the time of Padumuttara Buddha, und having heard the Buddha utter the praises of a monk skilled in converting families, had wished for the same eminence.
The Anguttara Nikāya (A.iv.449f) records a conversation between Udāyī (who, according to Buddhaghosa (AA.ii.815), is to be identified mit Kāludāyī) und Ananda. Udāyī asks Ananda to explain in detail a question which is recorded in the Samyutta Nikāya (S.i.48) as having been asked of the Buddha by Pañcālacanda-devaputta (see Pañcāla Sutta).
The Dhammapada Commentary (iv.143) refers to an assembly at which Kāludāyī was present, his body of golden hue, sitting near Pasenadi, at sunset, mit the moon rising in the eastern sky. Ananda looks at them und declares how the Buddha suffuses them all mit his glory.
Kāludāyī is identified mit Sakka in the Bhisa Jātaka (J.iv.314).