DATETIME sensor template returns -1 in x.timestamp

ESPHome
1

I have a DATETIME template with an ON_VALUE option within that is a lambda that uses x.timestamp. This has contained number of seconds of the date time entered in the field. But now contains -1
When the pop-up is closed the date field on screen contains 07/02/2106
This has started happening since either 2026.3.0 or 2026.3.1

Code:

esphome:
  name: test-datetime
  friendly_name: Test DateTime

esp8266:
  board: d1_mini

# Enable logging
logger:

# Enable Home Assistant API
api:
  encryption:
    key: "redacted"

ota:
  - platform: esphome
    password: "redacted"

wifi:
  ssid: !secret wifi_ssid
  password: !secret wifi_password

  # Enable fallback hotspot (captive portal) in case wifi connection fails
  ap:
    ssid: "Test-Datetime Fallback Hotspot"
    password: "redacted"

captive_portal:

globals:
  - id: durationSeconds
    type: int
    restore_value: no
    initial_value: "0"

time:
  - platform: homeassistant
    id: ha_time

datetime:
  - platform: template
    name: Unlock after time
    icon: mdi:timer-lock-open-outline
    type: DATETIME
    time_id: ha_time
    optimistic: True
    on_value: 
        then:
          - lambda: |-
              id(durationSeconds) = (x.timestamp - id(ha_time).now().timestamp);
              ESP_LOGW("main", "Duration (Seconds): %d", id(durationSeconds));
              ESP_LOGW("main", "timeNow (Seconds): %d", id(ha_time).now().timestamp);
              ESP_LOGW("main", "End Time (Seconds): %d", x.timestamp);

log file:

[12:49:10.019][D][api.connection:2440]: Home Assistant 2026.3.4 (192.168.1.132): connected
[12:49:40.207][D][datetime.datetime_entity:127]: 'Unlock after time' - Setting
[12:49:40.212][D][datetime.datetime_entity:130]:  Year: 2026
[12:49:40.215][D][datetime.datetime_entity:133]:  Month: 3
[12:49:40.221][D][datetime.datetime_entity:136]:  Day: 27
[12:49:40.226][D][datetime.datetime_entity:139]:  Hour: 0
[12:49:40.232][D][datetime.datetime_entity:142]:  Minute: 0
[12:49:40.235][D][datetime.datetime_entity:145]:  Second: 0
[12:49:40.243][D][datetime.datetime_entity:048]: 'Unlock after time' >> 2026-03-27 00:00:00
[12:49:40.248][W][main:052]: Duration (Seconds): -1774615780
[12:49:40.254][W][main:053]: timeNow (Seconds): 1774615779
[12:49:40.259][W][main:054]: End Time (Seconds): -1

Previous output:

[11:30:36.453][D][datetime.datetime_entity:127]: 'Unlock after time' - Setting
[11:30:36.454][D][datetime.datetime_entity:130]:  Year: 2026
[11:30:36.477][D][datetime.datetime_entity:133]:  Month: 3
[11:30:36.478][D][datetime.datetime_entity:136]:  Day: 27
[11:30:36.478][D][datetime.datetime_entity:139]:  Hour: 12
[11:30:36.478][D][datetime.datetime_entity:142]:  Minute: 0
[11:30:36.479][D][datetime.datetime_entity:145]:  Second: 0
[11:30:36.479][D][datetime.datetime_entity:048]: 'Unlock after time' >> 2026-03-27 12:00:00
[11:30:36.479][W][main:292]: Duration (Seconds): 1764
[11:30:36.480][W][main:293]: timeNow (Seconds): 1774611036
[11:30:36.481][W][main:294]: End Time (Seconds): 1774612800
2

My first step would be to change:

type: DATETIME

to

type: datetime

in line with the docs, recognising the apparent error in the config section that says type must be date or time then provides examples with datetime.

3

Thanks for the suggestion, but it makes no difference. Interestingly the type-ahead prompt gives DATETIME in uppercase.

4

Was this related to breaking changes in the recent release notes, about using the new API?
You do read the release notes carefully before hitting the update button don’t you?

5

I did note the changes to time component, but I’m not using any of the quoted functions - " ::mktime(), ::strftime(), setenv("TZ", ...), or tzset()". I’m only using .now() and .timestamp

6

I have simplified the code.

Removed the ON_VALUE entry
Removed the reference to the time component

The date passed from the pop-up back to the screen field is still 07/02/2106

7

I raised this on GITHUB. It is a bug and will be fixed in 2026.3.2