diff --git a/fabrictestbed_extensions/fablib/slice.py b/fabrictestbed_extensions/fablib/slice.py
index 10fd697e..ca22a560 100644
--- a/fabrictestbed_extensions/fablib/slice.py
+++ b/fabrictestbed_extensions/fablib/slice.py
@@ -1705,7 +1705,7 @@ def renew(self, end_date: str = None, days: int = None, **kwargs):
             days = (end - datetime.now(timezone.utc)).days
 
         # Directly pass the kwargs to submit
-        self.submit(lease_in_days=days, post_boot_config=False, **kwargs)
+        self.submit(lease_in_hours=(days * 24), post_boot_config=False, **kwargs)
 
     def build_error_exception_string(self) -> str:
         """
@@ -2235,7 +2235,8 @@ def submit(
         wait_ssh: bool = True,
         extra_ssh_keys: List[str] = None,
         lease_start_time: datetime = None,
-        lease_in_days: int = None,
+        lease_end_time: datetime = None,
+        lease_in_hours: int = None,
         validate: bool = False,
     ) -> str:
         """
@@ -2272,12 +2273,17 @@ def submit(
         :param extra_ssh_keys: Optional list of additional SSH public keys to be installed in the slivers of this slice
         :type extra_ssh_keys: List[str]
 
-        :param lease_start_time: Optional lease start in UTC time format: %Y-%m-%d %H:%M:%S %z
+        :param lease_start_time: Optional lease start time in UTC format: %Y-%m-%d %H:%M:%S %z.
+                           Specifies the beginning of the time range to search for available resources valid for `lease_in_hours`.
         :type lease_start_time: datetime
 
-        :param lease_in_days: Optional lease duration in days, by default the slice is active for 24 hours i.e 1 day,
-                              only used for create.
-        :type lease_in_days: int
+        :param lease_end_time: Optional lease end time in UTC format: %Y-%m-%d %H:%M:%S %z.
+                         Specifies the end of the time range to search for available resources valid for `lease_in_hours`.
+        :type lease_end_time: datetime
+
+        :param lease_in_hours: Optional lease duration in hours. By default, the slice remains active for 24 hours (1 day).
+                               This parameter is only applicable during creation.
+        :type lease_in_hours: int
 
         :param validate: Validate node can be allocated w.r.t available resources
         :type validate: bool
@@ -2295,26 +2301,18 @@ def submit(
         # Generate Slice Graph
         slice_graph = self.get_fim_topology().serialize()
 
-        lease_start_time_str = None
-        if lease_start_time:
-            lease_start_time_str = lease_start_time.strftime("%Y-%m-%d %H:%M:%S %z")
+        start_time_str = lease_start_time.strftime("%Y-%m-%d %H:%M:%S %z") if lease_start_time else None
+        end_time_str = lease_end_time.strftime("%Y-%m-%d %H:%M:%S %z") if lease_end_time else None
 
-        lease_end_time = None
-        lease_end_time_str = None
-        if lease_in_days:
-            start_time = (
-                lease_start_time if lease_end_time else datetime.now(timezone.utc)
-            )
-            lease_end_time = start_time + timedelta(days=lease_in_days)
-            lease_end_time_str = (start_time + timedelta(days=lease_in_days)).strftime(
-                "%Y-%m-%d %H:%M:%S %z"
-            )
+        # Create slice now or Renew slice
+        if lease_in_hours and not lease_start_time and not lease_end_time:
+            end_time_str = (datetime.now(timezone.utc) + timedelta(hours=lease_in_hours)).strftime("%Y-%m-%d %H:%M:%S %z")
 
         # Request slice from Orchestrator
         if self._is_modify():
-            if lease_in_days:
+            if lease_in_hours:
                 return_status, result = self.fablib_manager.get_manager().renew(
-                    slice_object=self.sm_slice, new_lease_end_time=lease_end_time_str
+                    slice_object=self.sm_slice, new_lease_end_time=end_time_str
                 )
             else:
                 (
@@ -2342,15 +2340,6 @@ def submit(
                 # this will throw an informative exception
                 FABRICSSHKey.get_key_length(ssh_key)
 
-            if (
-                lease_start_time
-                and lease_end_time
-                and (lease_end_time - lease_start_time) < timedelta(minutes=60)
-            ):
-                raise Exception(
-                    "Requested Lease Time range should be at least 60 minutes long!"
-                )
-
             (
                 return_status,
                 slice_reservations,
@@ -2358,8 +2347,9 @@ def submit(
                 slice_name=self.slice_name,
                 slice_graph=slice_graph,
                 ssh_key=ssh_keys,
-                lease_end_time=lease_end_time_str,
-                lease_start_time=lease_start_time_str,
+                lease_end_time=end_time_str,
+                lease_start_time=start_time_str,
+                lifetime=lease_in_hours
             )
             if return_status == Status.OK:
                 logging.info(
diff --git a/pyproject.toml b/pyproject.toml
index f12852f4..66cb5e2e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "flit_core.buildapi"
 
 [project]
 name = "fabrictestbed-extensions"
-version = "1.7.4"
+version = "1.8.0b1"
 description = "FABRIC Python Client Library and CLI Extensions"
 authors = [
   { name = "Paul Ruth", email = "pruth@renci.org" },
@@ -20,7 +20,7 @@ dependencies = [
     "ipyleaflet",
     "ipycytoscape",
     "tabulate",
-    "fabrictestbed==1.7.8",
+    "fabrictestbed==1.8.0b1",
     "paramiko",
     "jinja2>=3.0.0",
     "pandas",