I'll bet you are right... Here is a cut from the JSON data the WLL provides to me, note "ts":
{
"data": {
"did": "001D0A712A19",
"ts": 1596411603,
"conditions": [
{
"lsid": 333561,
"data_structure_type": 1,
"txid": 1,
"temp": 84.6,
"hum": 36.7,
"dew_point": 55.2
I just looked it up, it is Unix time, thanks!!! I run a linux box and did not notice it, go figure!