## Syntax ```mermaid %%{init: { 'theme': 'base', 'flowchart': { 'padding': '7', 'nodeSpacing': '20', 'rankSpacing': '20' }, 'themeVariables': { 'fontSize': '11px', 'fontFamily': 'Arial' } }}%% flowchart LR Start((START)) --> IS_DATE[IS_DATE]:::quoted IS_DATE --> End((END)) ``` The `IS_DATE` SQL function determines whether a value is a valid number according to the specified format. When true, the value can be converted by `to_date`. Parameters: - Input: value to convert. - Format: format mask. Optional; defaults to local style. The list of format masks is available in [[Format Masks]]. Returns: true when the value can be converted to a date, false otherwise.