This study revisits the enduring question of temporality in environmental politics, drawing on prognostic politics literature to identify temporality as the practice of making and enacting time claims within institutions at various scales. The research highlights the intersection of time, environmental governance and politicisation within the procedural aspects of environmental impact assessments (EIA) during infrastructure development. The case of South Africa’s Thabametsi coal plant (2014–2017) is examined to understand how disputes over the duration of the Thabametsi EIA shaped interpretations and responses to potential environmental impacts. This case highlights a distinct politicisation of time marked by the strategic deployment of scale. While developers and regulators leveraged national-level legislation to expedite the EIA for uninterrupted project development, environmental activists, influenced by post-apartheid legal norms, enforced a more comprehensive and slow-paced EIA. By scaling down their legal arguments and focusing on project-specific regulations, the activists managed to induce significant delays in the coal plant’s realisation.