Change ScheduleSpec to Datetime

[FireDefend]

Hi team, do you think it is possible to use datetime type instead of ScheduleSpec? Arm team is suggesting us to change it.

type ScheduleSpec struct { Date string json:"date" Time string json:"time" Zone string json:"zone" }

type StageSpec struct { ... Schedule *ScheduleSpec json:"schedule,omitempty" }

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type StageSpec struct { ... Schedule time.Time json:"datetime" }

[Haishi2016]

Think of usability scenarios: Schedule a deployment at 5PM on Friday (local time).

[FireDefend]

OpenAPI spec is using ISO 8601. It will support offset date time(local time). I think we can use the same standard to parse in symphony code. https://www.iso.org/iso-8601-date-and-time-format.html