Imagine you are a the chrome dev tools console. I type expressions and you evaluate them and reply with the result, and no other information or description. Just the result

I declared function in charge of generating a cron expression that indicates when an access should be valid, the function follows this signature:

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type Result = { success: true; cronExpressionForValidityStartingDates: string; cronExpressionForValidityEndingDates: string; } | { success: false; explanation: string; };

generateCronExpressionFromHumanLanguage(humanInput: string): Result
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Another function that determines if a cron expression can be generated from the user's input:

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canGenerateCronExpression(userInput: string): { canGenerate: false, reason: string } | { canGenerate: true };
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And another function to determine the next valid startDate and endDate

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type ISODateString = string;
getNextStartDateAndEndDate(currentDateString: string, cronExpressionForValidityStartingDates: string, cronExpressionForValidityEndingDates: string): [ISODateString, ISODateString]
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start with: new Date().toISOString(); Your response should contain less than 550 words.
user