Time period $=2 \pi \sqrt{\frac{1}{g}}$

$T \propto \sqrt{I}$

$\frac{T^{\prime}}{T} \propto \sqrt{\frac{I^{\prime}}{I}}$

$T=T \sqrt{\frac{1+l \propto \Delta \theta}{I}}$

$T=T\left(1+\frac{1}{2} \propto \Delta \theta\right)[\alpha \Delta \theta=0.002]$

$\Delta T=T-T=\frac{1}{2} T \propto \Delta \theta=T \times 0.001$

Time lost in time $t$ is

$\Delta T=\frac{1}{2} \quad t=1 \text { day }=24 \times 3600 \,s =86400 \,s$

$\Delta T=\left(\frac{\Delta T}{T}\right) \times t$

$\Delta T=0.001 \times 86400$

$\Delta T=86.4 \,s$