'And' Conditional in custom field

[rwb139]

How can I use the 'and' conditional in a custom field? I am trying to do so and it keeps giving me this error. Any help is appreciated!

[rwb139 · Accepted solution]

Solved it by converting to this if statement:

if(QuarterStart(AddMonths(today(),-9))>=date(lease_from),if(QuarterStart(AddMonths(today(),-9))<=date(lease_to),'y','n'),
if(QuarterEnd(AddMonths(today(),-9))>=date(lease_from),if(QuarterEnd(AddMonths(today(),-9))<=date(lease_to),'y','n'),'n'))