Calculate the annualised return for cash flows on different dates, such as SIPs, top-ups and redemptions.
Find x such that Σ CF_k ÷ (1 + x)^((d_k − d_0)/365) = 0. Solved with Newton–Raphson from 10%, falling back to bisection between −99.99% and 1000%.
−₹10,000 on 1 Jan 2020 and +₹11,000 on 1 Jan 2021 gives an XIRR of 9.97% (2020 had 366 days).