I'm a developer and we are using Quartz.Net, widely used scheduling library with SQL backing store to run cluster of jobs servers (VMs on ESXI cluster).

Quartz.Net [requires](https://www.quartz-scheduler.net/documentation/quartz-2.x/tutorial/advanced-enterprise-features.html) that time will be synchronized between job server instances and recommends using NTP for it.

> 
> The clocks must be within a second of each other.
> 
> 
> 

Our sysadmins using windows NTP to sync time with domain controller. Synchronization of VMs with ESXI host is off.

They keep insisting that's "within second" is not correct requirement and that cannot be met w/o hardware GPS-syncing devices. Their SLA & monitoring level are "within 3 minutes". 

We are experiencing periodic (once in 2-3 months) Quartz instances out-of-sync behavior that consistent with time being out of sync. 

1. Is it correct for us to ask for "within second" or we need to ditch Quartz entirely?
2. If yes, what changes are recommended for our setup?