# Time Sync Check ## Issue: Node clocks are not synchronized ## Symptoms As with all advanced checks, there is no obvious symptoms until you have missed a block. ## Check To check if you are having this issue, simultaneously check the time of your nodes. You can also optionally check the activity time stamps of your producer and relay logs but this is not necessary. ## Root Cause and Avoidance If you are not using a time synchronization service, the time kept by your servers will slowly drift away from the actual network time. Please do not take this lightly as in extreme cases, this may lead to you failing to mint blocks and I have personally met an SPO who experienced this issue. Note that in some cases, especially with servers running from Cloud providers, this issue may not appear as there may be underlying architecture that already synchronizes server times. Nevertheless, it is always good practice to run a time synchronization tool like chrony to avoid time issues from happening. ## Remediation Install chrony on all of your nodes. You can follow this tutorial from Coincashew to do this: {% embed url="" %} Note that whether you have already missed blocks or not, it is always recommended to run chrony on all of your nodes. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://blockchainlens.gitbook.io/cardano-spot-check/advanced-checks/time-sync-check.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.