Acharya Bhikshu Swami Badi Teras is traditionally observed on Jeth Vad Teras, not as a fixed Gregorian date. In August 2026, the Teras tithis shown in the Jain calendar are 10 August 2026 and 25 August 2026. ( jainknowledge.com)

If you mean the Acharya Bhikshu-related observance, it is the tithi-based Teras that matters, rather than the August month itself. ( jainknowledge.com)