> ## Documentation Index
> Fetch the complete documentation index at: https://glossary.micahealth.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Study start date

The precise date when the first participant is enrolled in a clinical study, with an "estimated" start date reflecting researchers' initial projection of when enrollment might begin.

[*Source*](https://clinicaltrials.gov/study-basics/glossary)