A very simple python script to calulate slots

python -i CardanoSlots.py

A interactive terminal will open
Get a unix time from here if you don't know how
Use 'getSlotFromUnixTime' to get a slot
You can check using getUTCEsitmateFromSlot

mySlot = getSlotFromUnixTime(<YOUR_TIME_HERE>)
getUTCEstimateFromSlot(mySlot)

In the event of a hard fork in which times are affected this code will be deprecated.