Quasar lifetimes from literature as a function of redshift. Measurements using HI proximity zones along the line of sight are shown with blue squares (Eilers et al. 2018, 2021; Davies et al. 2019, 2020; Andika et al. 2020; Morey et al. 2021), studies using quasar clustering are depicted with red circles (Shen et al. 2007; Shankar et al. 2010; White et al. 2012; Laurent et al. 2017). Measurements inferred from the duty cycle of the quasar host population are shown with grey triangles (Yu & Tremaine 2002; Chen & Gnedin 2018), while those using extends of Lyα nebulae are depicted with purple pentagons (Trainor & Steidel 2013; Cantalupo et al. 2014; Hennawi et al. 2015; Borisova et al. 2016). Furthermore, quasar lifetime estimates calculated from the HeII proximity zones are shown as light brown crosses (Khrykin et al. 2019, 2021; Worseck et al. 2021), and studies using the transverse proximity effect are marked with a pink diamond (Kirkman & Tytler 2008; Keel et al. 2012; Schmidt et al. 2017, 2018; Oppenheimer et al. 2018; Bosman et al. 2020). Our estimation of t_Q for J0910-0414 is depicted with a yellow star. Adapted from Eilers et al. (2021).