Its equal distance between raffles city and tanjong pagar mrt,
but its easier for you to take the lau pa sat exit from raffles,
head towards lau pa sat, pass it and carry on walking straight till
you reach ya kun. 
If you really want to meet, come earlier say 1150, and go lunch,
not come 1230, then 15 mins i got to go back work. Tuesday i most
prob in, wed high chance I not. 