Śrī Gaṇeśa Caturthī
Manifestation of Lord Gaṇapati, the Supreme Remover of Obstacles
Monday, 29 August 2310

In Vedic astronomy, daylight is divided into five equal segments: Prātaḥ, Saṅgava, Madhyāhna, Aparāhna, and Sāyaṅkāla. The Śiva Purāṇa and Gaṇeśa Purāṇa declare that Lord Gaṇeśa appeared during Madhyāhna (the midday third fifth of daylight). Gaṇeśa Avāhana (invocation) and Prāṇa Pratiṣṭhā (consecration of the clay idol) are uniquely performed at midday when solar and vital energies reach their cosmic zenith.
From the pañchāṅga
By local reckoning this is kept on Sunday, 28 August or Monday, 29 August across the world, the date above is for your location.
How it is observed
The clay mūrti of Gaṇeśa is installed and worshipped at madhyāhna with modaka and dūrvā grass over the festival days, then carried in procession for immersion (visarjana). Those who fast keep the monthly Vināyaka Caturthī form, see the vrata.