Have fluid date (text option) on the "add a contract" tab.
As the dates are usually 'so many working dates from the day hereof.' entering a date prior to signing is impossible.
As you type up an new agreement (prior to being signed) you need to enter the dates. You can not possibly predict when the contract will be signed so need more of an open option. Quite often deposit is entered as 10% of the purchase price rather than as a set $ amount. Finance date is usually 5 working days from the date hereof. If a property is tenanted you need to give 47 days notice, so that usually is entered 47 days from the date hereof.
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